Merge pull request #920 from heroku/python/382

Build and release Python 3.8.2

.dockerignore

@@ -0,0 +1 @@
+.git/

.github/CODEOWNERS

@@ -0,0 +1 @@
+* @heroku/languages

.github/PULL_REQUEST_TEMPLATE.md

@@ -0,0 +1,8 @@
+<!-- Hi and welcome to the Heroku Python buildpack repository!
+
+If you meant to open a PR against a fork instead of upstream, please adjust the base branch:
+https://help.github.com/articles/changing-the-base-branch-of-a-pull-request/
+
+Otherwise thank you in advance for your Pull Request - just remember to
+include as much information as possible to help the reviewers :-)
+-->

.github/workflows/check_changelog.yml

@@ -0,0 +1,12 @@
+name: Check Changelog
+
+on: [pull_request]
+
+jobs:
+ build:
+   runs-on: ubuntu-latest
+   steps:
+   - uses: actions/checkout@v1
+   - name: Check that CHANGELOG is touched
+     run: |
+       cat $GITHUB_EVENT_PATH | jq .pull_request.title |  grep -i '\[\(\(changelog skip\)\|\(ci skip\)\)\]' ||  git diff remotes/origin/${{ github.base_ref }} --name-only | grep CHANGELOG.md

.gitignore

@@ -1,2 +1,12 @@
 *.pyc
 site
+.DS_Store
+
+/.envrc
+repos/*
+
+#Venv
+buildpack/*
+
+builds/dockerenv.staging*
+builds/dockerenv.production

.pre-commit-config.yaml

@@ -0,0 +1,7 @@
+repos:
+-   repo: https://github.com/pre-commit/pre-commit-hooks
+    rev: v2.3.0
+    hooks:
+    -   id: check-yaml
+    -   id: end-of-file-fixer
+    -   id: trailing-whitespace

.travis.yml

@@ -0,0 +1,39 @@
+language: ruby
+dist: trusty
+sudo: required
+
+rvm:
+- 2.4.4
+before_script:
+  - gem install bundler -v 1.16.2
+  - bundle exec hatchet ci:setup
+
+script:
+  - docker build --pull --tag travis-build-cedar-14 --file $(pwd)/builds/cedar-14.Dockerfile .
+  - docker run --rm -e "STACK=cedar-14" -e "USE_STAGING_BINARIES=$USE_STAGING_BINARIES" travis-build-cedar-14 bash $TESTFOLDER
+  - docker build --pull --tag travis-build-heroku-16 --file $(pwd)/builds/heroku-16.Dockerfile .
+  - docker run --rm -e "STACK=heroku-16" -e "USE_STAGING_BINARIES=$USE_STAGING_BINARIES" travis-build-heroku-16 bash $TESTFOLDER
+  - docker build --pull --tag travis-build-heroku-18 --file $(pwd)/builds/heroku-18.Dockerfile .
+  - docker run --rm -e "STACK=heroku-18" -e "USE_STAGING_BINARIES=$USE_STAGING_BINARIES" travis-build-heroku-18 bash $TESTFOLDER
+
+jobs:
+  include:
+  - stage: Bash linting (shellcheck)
+    sudo: false
+    script: make check
+  - stage: Hatchet Integration
+    if: branch = master
+    name: Run Hatchet
+    script: "bundle exec rspec"
+env:
+  matrix:
+    - TESTFOLDER=test/run-deps
+    - TESTFOLDER=test/run-versions
+    - TESTFOLDER=test/run-features
+  global:
+    - HATCHET_RETRIES=3
+    - IS_RUNNING_ON_CI=true
+    - HATCHET_APP_LIMIT=5
+    - HATCHET_DEPLOY_STRATEGY=git
+    - secure: yjtlPE5FbVxTKnjUy/tZUBgSEf4qADD3QOxtgziuid73S0U/1IEXlMGFULsQzIjtlHKmHeywZqpVVEpthIH4RuT7uoX1Pb7SSM/g0T8fT3VoEFbFK1uYl0oZQbUS4Klxv9tPiumj8if3m6ULEGIz1X0wZcMOC0tMLwVCnwmap0E=
+    - secure: ZeFTHWwnpIKE9nAqs88ocmiQh7bKce84lilGm5J23nf3N6V4wNyLwqlkvsM008WGBCaOg9AUx7ZunasT0ANsR5gLP3eV2UUg7ILdRgV2Gy13eNRFheC4PHdN92RqQ3aKoqlIv2K999xlhVjod0NzhkQQXB6PddfQINbuU7ks6As=

CHANGELOG.md

@@ -0,0 +1,515 @@
+# Python Buildpack Changelog
+
+# Master
+
+- Python 3.8.2 now available.
+
+
+--------------------------------------------------------------------------------
+
+# 163 (2020-02-20)
+
+- Update requirements.txt builds to use Pip 20.0.2
+- Download get-pip.py to tmpdir instead of root dir
+
+# 163 (2019-12-23)
+
+- New pythons released:
+  Python 3.8.1, 3.7.6, 3.6.10 (CPython)
+  Beta Release: Pypy 2.7 and 3.6, version 7.2.0
+
+# 162 (2019-12-06)
+
+- Bug fix: fragile sqlite3 install
+
+# 161 (2019-12-2)
+
+- Bug fix: Sqlite3 version bump
+
+# 160 (2019-10-23)
+
+- Bugfix: Pipenv no longer installs twice in CI
+
+# 159 (2019-10-22)
+
+- Python 2.7.17 now available on Heroku 18 and 16.
+
+# 158 (2019-10-21)
+
+- Python 3.7.5 and 3.8.0 now available on Heroku 18 and 16.
+- Add support for Python 3.8 branch
+- Sqlite3 Update:
+  - Test Improvements
+- Add support for staging binary testing
+
+# 157 (2019-09-18)
+
+- Typo fixes
+
+# 156 (2019-09-12)
+
+- Python 3.6.9 and 3.7.4 now available.
+
+- Move get-pip utility to S3
+- Build utility and documentation updates
+- Bump Hatchet tests to point at new default python version.
+
+# 155 (2019-08-22)
+
+add docs and make target for heroku-18 bob builds
+
+# 154 (2019-07-17)
+
+Fix python 3.5.7 formula actually building 3.7.2
+
+# 153 (2019-06-21)
+
+Hotfix for broken heroku-16 deploys
+
+# 152 (2019-04-04)
+
+Python 3.7.3 now available.
+
+# 151 (2019-03-21)
+
+Python 3.5.7 and 3.4.10 now available on all Heroku stacks.
+
+# 150 (2019-03-13)
+
+Python 2.7.16 now available on all Heroku stacks.
+
+# 149 (2019-03-04)
+
+Hotfix for broken Cedar 14 deploys
+
+# 148 (2019-02-21)
+
+No user facing changes, improving internal metrics
+
+# 147 (2019-02-07)
+
+Python 3.7.2 and 3.6.8 now available on all Heroku stacks.
+
+# 146 (2018-11-11)
+
+Python 3.7.1, 3.6.7, 3.5.6 and 3.4.9 now available on all Heroku stacks.
+
+# 145 (2018-11-08)
+
+Testing and tooling expanded to better support new runtimes
+
+# 144 (2018-10-10)
+
+Switch to cautious upgrade for Pipenv install to ensure the pinned pip version
+is used with Pipenv
+
+# 143 (2018-10-09)
+
+Add support for detecting SLUGIFY_USES_TEXT_UNIDECODE, which is required to
+install Apache Airflow version 1.10 or higher.
+
+# 142 (2018-10-08)
+
+Improvements to Python install messaging
+
+# 139, 140, 141
+
+No user-facing changes, documenting for version clarity
+
+# 138 (2018-08-01)
+
+Use stack image SQLite3 instead of vendoring
+
+# 137 (2018-07-17)
+
+Prevent 3.7.0 from appearing as unsupported in buildpack messaging.
+
+# 136 (2018-06-28)
+
+Upgrade to 3.6.6 and support 3.7.0 on all runtimes.
+
+# 135 (2018-05-29)
+
+Upgrade Pipenv to v2018.5.18.
+
+# 134 (2018-05-02)
+
+Default to 3.6.5, bugfixes.
+
+# 133
+
+Fixes for Pip 10 release.
+
+# 132
+
+Improve pip installation, with the release of v9.0.2.
+
+# 131
+
+Fix bug with pip.
+
+# 130
+
+Better upgrade strategy for pip.
+
+# 129
+
+Don't upgrade pip (from v128).
+
+# 128
+
+Upgrade pip, pin to Pipenv v11.8.2.
+
+# 127
+
+Pin to Pipenv v11.7.1.
+
+# 126
+
+Bugfixes.
+
+# 125
+
+Bugfixes.
+
+# 124
+
+Update buildpack to automatically install `[dev-packages]` during Heroku CI Pipenv builds.
+
+- Skip installs if Pipfile.lock hasn't changed, and uninstall stale dependencies with Pipenv.
+- Set `PYTHONPATH` during collectstatic runs.
+- No longer warn if there is no `Procfile`.
+- Update Pipenv's "3.6" runtime specifier to point to "3.6.4".
+
+# 123
+
+Update gunicorn `init.d` script to allow overrides.
+
+# 122
+
+Update default Python to v3.6.4.
+
+# 121
+
+Update default Python to v3.6.3.
+
+# 120
+
+Use `$ pipenv --deploy`.
+
+# 119
+
+Improvements to Pipenv support, warning on unsupported Python versions.
+
+- We now warn when a user is not using latest 2.x or 3.x Python.
+- Heroku now supports `[requires]` `python_full_version` in addition to `python_version`.
+
+# 118
+
+Improvements to Pipenv support.
+
+# 117
+
+Bug fix.
+
+# 116
+
+Vendoring improvements.
+
+- Geos libraries should work on Heroku-16 now.
+- The libffi/libmemcached vendoring step is now skipped on Heroku-16 (since they are installed in the base image).
+
+# 115
+
+Revert a pull request.
+
+- No longer using `sub_env` for `pip install` step.
+
+# 114
+
+- Bugfixes.
+
+Blacklisting `PYTHONHOME` and `PYTHONPATH` for older apps. Upgrades to nltk support.
+
+# 113
+
+Updates to Pipenv support.
+
+# 112
+
+Bugfix.
+
+- Fixed grep output bug.
+
+# 111
+
+Linting, bugfixes.
+
+# 110
+
+Update default Python to 3.6.2.
+
+# 109
+
+Update Default Python to 3.6.1, bugfixes.
+
+- Fixed automatic pip uninstall of dependencies removed from requirements.txt.
+
+# 108
+
+Fix output for collectstatic step.
+
+# 107
+
+Bugfix for C dependency installation.
+
+# 106
+
+ Don't install packages that could mess up packaging.
+
+ - The Python buildpack will automatically remove `six`, `pyparsing`, `appdirs`,
+   `setuptools`, and `distribute` from a `requirements.txt` file now, as these
+   packages are provided by the Python buildpack.
+
+ # 105
+
+ Improvements to output messaging.
+
+# 104
+
+General improvements.
+
+- Fix for Heroku CI.
+- Use `pkg_resources` to check if a distribution is installed instead of
+  parsing `requirements.txt`. ([#395][395])
+
+[395]: https://github.com/heroku/heroku-buildpack-python/pull/395
+
+## 103
+
+Bug fixes and improvements.
+
+- Fix for Pipenv.
+- Fix for Heroku CI.
+- Improve handling of WEB_CONCURRENCY when using multiple buildpacks.
+- Adjust environment variables set during the build to more closely match those in the dyno environment (DYNO is now available, STACK is not).
+- Restore the build cache prior to running bin/pre_compile.
+
+## 102
+
+Buildpack code cleanup.
+
+- Improved messaging around NLTK.
+
+## 101
+
+Updated setuptools installation method.
+
+- Improved pipenv support.
+
+## 100
+
+Preliminary pipenv support.
+
+## 99
+
+Cleanup.
+
+## 98
+
+Official NLTK support and other improvements.
+
+- Support for `nltk.txt` file for declaring corpora to be downloaded.
+- Leading zeros for auto-set WEB_CONCURRENCY.
+
+## 97
+
+Improved egg-link functionality.
+
+## 96
+
+Bugfix.
+
+## 95
+
+Improved output support.
+
+## v94
+
+Improved support for PyPy.
+
+## v93
+
+Improved support for PyPy.
+
+## v92
+
+Improved cache functionality and fix egg-links regression.
+
+## v91
+
+Bugfix, rolled back to v88.
+
+## v90
+
+Bugfix.
+
+## v89
+
+Improved cache functionality and fix egg-links regression.
+
+## v88
+
+Fixed bug with editable pip installations.
+
+## v87
+
+Updated default Python 2.7.13.
+
+- Python 2.7.13 uses UCS-4 build, more compatibile with linux wheels.
+- Updated setuptools to v32.1.0.
+
+## v86
+
+Refactor and multi-buildpack compatibility.
+
+## v85
+
+Packaging fix.
+
+## v84
+
+Updated pip and setuptools.
+
+- Updated pip to v9.0.1.
+- Updated setuptools to v28.8.0.
+
+## v83
+
+Support for Heroku CI.
+
+- Cffi support for argon2
+
+## v82 (2016-08-22)
+
+Update to library detection mechnisms (pip-pop).
+
+- Updated setuptools to v25.5.0
+
+## v81 (2016-06-28)
+
+Updated default Python to 2.7.11.
+
+- Updated pip to v8.1.2.
+- Updated setuptools to v23.1.0.
+
+## v80 (2016-04-05)
+
+Improved pip-pop compatibility with latest pip releases.
+
+## v79 (2016-03-22)
+
+Compatibility improvements with heroku-apt-buildpack.
+
+## v78 (2016-03-18)
+
+Added automatic configuration of Gunicorn's `FORWARDED_ALLOW_IPS` setting.
+
+Improved detection of libffi dependency when using bcrypt via `Django[bcrypt]`.
+
+Improved GDAL support.
+
+- GDAL dependency detection now checks for pygdal and is case-insensitive.
+- The vendored GDAL library has been updated to 1.11.1.
+- GDAL bootstrapping now also installs the GEOS and Proj.4 libraries.
+
+Updated pip to 8.1.1 and setuptools to 20.3.
+
+## v77 (2016-02-10)
+
+Improvements to warnings and minor bugfix.
+
+## v76 (2016-02-08)
+
+Improved Django collectstatic support.
+
+- `$ python manage.py collectstatic` will only be run if `Django` is present in `requirements.txt`.
+- If collectstatic fails, the build fails. Full traceback is provided.
+- `$DISABLE_COLLECTSTATIC`: skip collectstatic step completely (not new).
+- `$DEBUG_COLLECTSTATIC`: echo environment variables upon collectstatic failure.
+- Updated build output style.
+- New warning for outdated Python (via pip `InsecurePlatform` warning).
+
+## v75 (2016-01-29)
+
+Updated pip and Setuptools.
+
+## v74 (2015-12-29)
+
+Added warnings for lack of Procfile.
+
+## v72 (2015-12-07)
+
+Updated default Python to 2.7.11.
+
+## v72 (2015-12-03)
+
+Added friendly warnings for common build failures.
+
+## v70 (2015-10-29)
+
+Improved compatibility with multi and node.js buildpacks.
+
+## v69 (2015-10-12)
+
+Revert to v66.
+
+## v68 (2015-10-12)
+
+Fixed .heroku/venv error with modern apps.
+
+## v67 (2015-10-12)
+
+Further improved cache compatibility with multi and node.js buildpacks.
+
+## v66 (2015-10-09)
+
+Improved compatibility with multi and node.js buildpacks.
+
+## v65 (2015-10-08)
+
+Reverted v64.
+
+## v64 (2015-10-08)
+
+Improved compatibility with multi and node.js buildpacks.
+
+## v63 (2015-10-08)
+
+Updated Pip and Setuptools.
+
+- Setuptools updated to v18.3.2
+- Pip updated to v7.1.2
+
+
+## v62 (2015-08-07)
+
+Updated Pip and Setuptools.
+
+- Setuptools updated to v18.1
+- Pip updated to v7.1.0
+
+## v61 (2015-06-30)
+
+Updated Pip and Setuptools.
+
+- Setuptools updated to v18.0.1
+- Pip updated to v7.0.3
+
+## v60 (2015-05-27)
+
+Default Python is now latest 2.7.10. Updated Pip and Distribute.
+
+- Default Python version is v2.7.10
+- Setuptools updated to v16.0
+- Pip updated to v7.0.1

Changelog.md

@@ -1,130 +0,0 @@
-## v14
-
-Features:
-
-* Full removal of Django settings injection for new apps.
-* Support for profile.d
-* Fresh app detection.
-* Update to Virtualenv v1.7.2
-* Updated to Pip v1.1 (patched)
-
-Bugfixes:
-
-* Default pip path exists action.
-
-## v13
-
-Bugfixes:
-
-* Fix pip quoting error.
-* Only talk about collectstatic in buildpack output when it's configured.
-
-## v12
-
-Bugfixes:
-
-* Catch database setting corner case.
-
-## v11
-
-Bugfixes:
-
-* Cleanup collectstatic output.
-
-
-## v10
-
-Bugfixes:
-
-* Check for collectstatic validity with --dry-run instead of --help for Django 1.4.
-
-## v9
-
-Bugfixes:
-
-* Unset PYTHONHOME in buildpack for [user_env_compile](http://devcenter.heroku.com/articles/labs-user-env-compile).
-
-## v8
-
-Features:
-
-* Disable Django collectstatic with `$DISABLE_COLLECTSTATIC` + [user_env_compile](http://devcenter.heroku.com/articles/labs-user-env-compile).
-
-Bugfixes:
-
-* Don't disbable injection for new Django apps.
-* Inform user of July 1, 2012 deprecation of Django injection.
-
-## v7
-
-Features:
-
-* Full removal of Django setting injection for new apps.
-* Automatic execution of collectstatic.
-* Suppress collectstatic errors via env SILENCE_COLLECTSTATIC.
-* Increase settings.py search depth to 3.
-* Search recursively from included requirements.txt files.
-
-
-## v6 (03/23/2012)
-
-Features:
-
-* Dist packages (setup.py) support.
-* Move new virtualenvs to `/app/.heroku/venv`.
-* Heavily improved Django app detection, accounting for `Django` in `requirements.txt`.
-* Literate [documentation](http://python-buildpack.herokuapp.com).
-* Default `$PYTHONHOME`, `$PYTHONPATH`, and `$LANG` configurations.
-* Disable Django setting injection with `$DISABLE_INJECTION` + [user_env_compile](http://devcenter.heroku.com/articles/labs-user-env-compile).
-* General code refactor and improved messaging.
-* Unit tests.
-
-Bugfixes:
-
-* Django 1.4 startproject template layout support.
-* Django `manage.py` location can now be independent from `settings.py`.
-
-## v5 (02/01/2012)
-
-Bugfixes:
-
-* Git requirements 100% work.
-
-
-## v4 (01/20/2012)
-
-Features:
-
-* Updated to virtualenv v1.7 with patched pip v1.2.
-* Actually activate created virtualenv within compile process.
-* Use distribute instead of deprecated setuptools.
-* Automatically destroy and rebuild corrupt virtualenvs.
-* Refactor django and pylibmc detection.
-
-Bugfixes:
-
-* Fixed `package==dev` in requirements with patched pip embedded within virtualenv. Patch upstreamed.
-* Minor curl/rm flag fixes (thanks, contributors!)
-
-
-## v3 (12/07/2011)
-
-Bugfixes:
-
-* Better django setup.py injection.
-
-
-## v2 (11/15/2011)
-
-Features:
-
-* Support for pylibmc and libmemcached +sasl.
-
-Bugfixes:
-
-* Detect when virtualenv is checked in and alert user.
-
-
-## v1 (10/01/2011)
-
-* Conception.

Gemfile

@@ -0,0 +1,6 @@
+source "https://rubygems.org"
+
+gem "rspec"
+gem "heroku_hatchet"
+gem "rspec-retry"
+gem "rake"

Gemfile.lock

@@ -0,0 +1,71 @@
+GEM
+  remote: https://rubygems.org/
+  specs:
+    activesupport (5.2.1)
+      concurrent-ruby (~> 1.0, >= 1.0.2)
+      i18n (>= 0.7, < 2)
+      minitest (~> 5.1)
+      tzinfo (~> 1.1)
+    concurrent-ruby (1.1.3)
+    diff-lcs (1.3)
+    erubis (2.7.0)
+    excon (0.62.0)
+    heroics (0.0.25)
+      erubis (~> 2.0)
+      excon
+      moneta
+      multi_json (>= 1.9.2)
+    heroku_hatchet (4.0.6)
+      excon (~> 0)
+      minitest-retry (~> 0.1.9)
+      platform-api (~> 2)
+      repl_runner (~> 0.0.3)
+      rrrretry (~> 1)
+      thor (~> 0)
+      threaded (~> 0)
+    i18n (1.1.1)
+      concurrent-ruby (~> 1.0)
+    minitest (5.11.3)
+    minitest-retry (0.1.9)
+      minitest (>= 5.0)
+    moneta (1.0.0)
+    multi_json (1.13.1)
+    platform-api (2.2.0)
+      heroics (~> 0.0.25)
+      moneta (~> 1.0.0)
+    rake (12.3.1)
+    repl_runner (0.0.3)
+      activesupport
+    rrrretry (1.0.0)
+    rspec (3.8.0)
+      rspec-core (~> 3.8.0)
+      rspec-expectations (~> 3.8.0)
+      rspec-mocks (~> 3.8.0)
+    rspec-core (3.8.0)
+      rspec-support (~> 3.8.0)
+    rspec-expectations (3.8.1)
+      diff-lcs (>= 1.2.0, < 2.0)
+      rspec-support (~> 3.8.0)
+    rspec-mocks (3.8.0)
+      diff-lcs (>= 1.2.0, < 2.0)
+      rspec-support (~> 3.8.0)
+    rspec-retry (0.6.1)
+      rspec-core (> 3.3)
+    rspec-support (3.8.0)
+    thor (0.20.3)
+    thread_safe (0.3.6)
+    threaded (0.0.4)
+    tzinfo (1.2.5)
+      thread_safe (~> 0.1)
+
+PLATFORMS
+  ruby
+
+DEPENDENCIES
+  heroku_hatchet
+  rake
+  rspec
+  rspec-retry
+
+BUNDLED WITH
+   1.16.3

LICENSE

@@ -1,6 +1,6 @@
 MIT License:
 
-Copyright (C) 2013 Heroku, Inc.
+Copyright (C) 2017 Heroku, Inc.
 
 Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
 

Makefile

@@ -1,5 +1,55 @@
 # These targets are not files
 .PHONY: tests
 
-tests:
+test: test-heroku-18 test-heroku-16 test-cedar-14
-	./bin/test
+
+check:
+	@shellcheck -x bin/compile bin/detect bin/release bin/test-compile bin/utils bin/warnings bin/default_pythons
+	@shellcheck -x bin/steps/collectstatic bin/steps/eggpath-fix  bin/steps/eggpath-fix2 bin/steps/gdal bin/steps/geo-libs bin/steps/mercurial bin/steps/nltk bin/steps/pip-install bin/steps/pip-uninstall bin/steps/pipenv bin/steps/pipenv-python-version bin/steps/pylibmc bin/steps/python
+	@shellcheck -x bin/steps/hooks/*
+
+test-cedar-14:
+	@echo "Running tests in docker (cedar-14)..."
+	@docker run -v $(shell pwd):/buildpack:ro --rm -it -e "STACK=cedar-14" heroku/cedar:14 bash -c 'cp -r /buildpack /buildpack_test; cd /buildpack_test/; test/run-deps; test/run-features; test/run-versions;'
+	@echo ""
+
+test-heroku-16:
+	@echo "Running tests in docker (heroku-16)..."
+	@docker run -v $(shell pwd):/buildpack:ro --rm -it -e "STACK=heroku-16" heroku/heroku:16-build bash -c 'cp -r /buildpack /buildpack_test; cd /buildpack_test/; test/run-deps; test/run-features; test/run-versions;'
+	@echo ""
+
+test-heroku-18:
+	@echo "Running tests in docker (heroku-18)..."
+	@docker run -v $(shell pwd):/buildpack:ro --rm -it -e "STACK=heroku-18" heroku/heroku:18-build bash -c 'cp -r /buildpack /buildpack_test; cd /buildpack_test/; test/run-deps; test/run-features; test/run-versions;'
+	@echo ""
+
+buildenv-heroku-16:
+	@echo "Creating build environment (heroku-16)..."
+	@echo
+	@docker build --pull -f $(shell pwd)/builds/heroku-16.Dockerfile -t python-buildenv-heroku-16 .
+	@echo
+	@echo "Usage..."
+	@echo
+	@echo "  $$ export AWS_ACCESS_KEY_ID=foo AWS_SECRET_ACCESS_KEY=bar  # Optional unless deploying"
+	@echo "  $$ bob build runtimes/python-2.7.13"
+	@echo "  $$ bob deploy runtimes/python-2.7.13"
+	@echo
+	@docker run -it --rm python-buildenv-heroku-16
+
+buildenv-heroku-18:
+	@echo "Creating build environment (heroku-18)..."
+	@echo
+	@docker build --pull -f $(shell pwd)/builds/heroku-18.Dockerfile -t python-buildenv-heroku-18 .
+	@echo
+	@echo "Usage..."
+	@echo
+	@echo "  $$ export AWS_ACCESS_KEY_ID=foo AWS_SECRET_ACCESS_KEY=bar  # Optional unless deploying"
+	@echo "  $$ bob build runtimes/python-2.7.13"
+	@echo "  $$ bob deploy runtimes/python-2.7.13"
+	@echo
+	@docker run -it --rm python-buildenv-heroku-18
+
+tools:
+	git clone https://github.com/kennethreitz/pip-pop.git
+	mv pip-pop/bin/* vendor/pip-pop/
+	rm -fr pip-pop

NOTICE

@@ -0,0 +1,137 @@
+This buildpack includes some vendorized packages to ease installation.
+
+jq license
+----------
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
+
+
+shunit2 license
+---------------
+
+Copyright © 2007 Free Software Foundation, Inc. <http://fsf.org/>
+
+Everyone is permitted to copy and distribute verbatim copies of this license document, but changing it is not allowed.
+
+This version of the GNU Lesser General Public License incorporates the terms and conditions of version 3 of the GNU General Public License, supplemented by the additional permissions listed below.
+
+0. Additional Definitions.
+
+As used herein, “this License” refers to version 3 of the GNU Lesser General Public License, and the “GNU GPL” refers to version 3 of the GNU General Public License.
+
+“The Library” refers to a covered work governed by this License, other than an Application or a Combined Work as defined below.
+
+An “Application” is any work that makes use of an interface provided by the Library, but which is not otherwise based on the Library. Defining a subclass of a class defined by the Library is deemed a mode of using an interface provided by the Library.
+
+A “Combined Work” is a work produced by combining or linking an Application with the Library. The particular version of the Library with which the Combined Work was made is also called the “Linked Version”.
+
+The “Minimal Corresponding Source” for a Combined Work means the Corresponding Source for the Combined Work, excluding any source code for portions of the Combined Work that, considered in isolation, are based on the Application, and not on the Linked Version.
+
+The “Corresponding Application Code” for a Combined Work means the object code and/or source code for the Application, including any data and utility programs needed for reproducing the Combined Work from the Application, but excluding the System Libraries of the Combined Work.
+
+1. Exception to Section 3 of the GNU GPL.
+
+You may convey a covered work under sections 3 and 4 of this License without being bound by section 3 of the GNU GPL.
+
+2. Conveying Modified Versions.
+
+If you modify a copy of the Library, and, in your modifications, a facility refers to a function or data to be supplied by an Application that uses the facility (other than as an argument passed when the facility is invoked), then you may convey a copy of the modified version:
+
+a) under this License, provided that you make a good faith effort to ensure that, in the event an Application does not supply the function or data, the facility still operates, and performs whatever part of its purpose remains meaningful, or
+b) under the GNU GPL, with none of the additional permissions of this License applicable to that copy.
+3. Object Code Incorporating Material from Library Header Files.
+
+The object code form of an Application may incorporate material from a header file that is part of the Library. You may convey such object code under terms of your choice, provided that, if the incorporated material is not limited to numerical parameters, data structure layouts and accessors, or small macros, inline functions and templates (ten or fewer lines in length), you do both of the following:
+
+a) Give prominent notice with each copy of the object code that the Library is used in it and that the Library and its use are covered by this License.
+b) Accompany the object code with a copy of the GNU GPL and this license document.
+4. Combined Works.
+
+You may convey a Combined Work under terms of your choice that, taken together, effectively do not restrict modification of the portions of the Library contained in the Combined Work and reverse engineering for debugging such modifications, if you also do each of the following:
+
+a) Give prominent notice with each copy of the Combined Work that the Library is used in it and that the Library and its use are covered by this License.
+b) Accompany the Combined Work with a copy of the GNU GPL and this license document.
+c) For a Combined Work that displays copyright notices during execution, include the copyright notice for the Library among these notices, as well as a reference directing the user to the copies of the GNU GPL and this license document.
+d) Do one of the following:
+0) Convey the Minimal Corresponding Source under the terms of this License, and the Corresponding Application Code in a form suitable for, and under terms that permit, the user to recombine or relink the Application with a modified version of the Linked Version to produce a modified Combined Work, in the manner specified by section 6 of the GNU GPL for conveying Corresponding Source.
+1) Use a suitable shared library mechanism for linking with the Library. A suitable mechanism is one that (a) uses at run time a copy of the Library already present on the user's computer system, and (b) will operate properly with a modified version of the Library that is interface-compatible with the Linked Version.
+e) Provide Installation Information, but only if you would otherwise be required to provide such information under section 6 of the GNU GPL, and only to the extent that such information is necessary to install and execute a modified version of the Combined Work produced by recombining or relinking the Application with a modified version of the Linked Version. (If you use option 4d0, the Installation Information must accompany the Minimal Corresponding Source and Corresponding Application Code. If you use option 4d1, you must provide the Installation Information in the manner specified by section 6 of the GNU GPL for conveying Corresponding Source.)
+5. Combined Libraries.
+
+You may place library facilities that are a work based on the Library side by side in a single library together with other library facilities that are not Applications and are not covered by this License, and convey such a combined library under terms of your choice, if you do both of the following:
+
+a) Accompany the combined library with a copy of the same work based on the Library, uncombined with any other library facilities, conveyed under the terms of this License.
+b) Give prominent notice with the combined library that part of it is a work based on the Library, and explaining where to find the accompanying uncombined form of the same work.
+6. Revised Versions of the GNU Lesser General Public License.
+
+The Free Software Foundation may publish revised and/or new versions of the GNU Lesser General Public License from time to time. Such new versions will be similar in spirit to the present version, but may differ in detail to address new problems or concerns.
+
+Each version is given a distinguishing version number. If the Library as you received it specifies that a certain numbered version of the GNU Lesser General Public License “or any later version” applies to it, you have the option of following the terms and conditions either of that published version or of any later version published by the Free Software Foundation. If the Library as you received it does not specify a version number of the GNU Lesser General Public License, you may choose any version of the GNU Lesser General Public License ever published by the Free Software Foundation.
+
+If the Library as you received it specifies that a proxy can decide whether future versions of the GNU Lesser General Public License shall apply, that proxy's public statement of acceptance of any version is permanent authorization for you to choose that version for the Library.
+
+get-pip.py license
+------------------
+
+Copyright (c) 2008-2016 The pip developers (see AUTHORS.txt file)
+
+Permission is hereby granted, free of charge, to any person obtaining
+a copy of this software and associated documentation files (the
+"Software"), to deal in the Software without restriction, including
+without limitation the rights to use, copy, modify, merge, publish,
+distribute, sublicense, and/or sell copies of the Software, and to
+permit persons to whom the Software is furnished to do so, subject to
+the following conditions:
+
+The above copyright notice and this permission notice shall be
+included in all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+
+pip-pop license
+---------------
+
+The MIT License (MIT)
+
+Copyright (c) 2014 Kenneth Reitz.
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in
+all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+THE SOFTWARE.

Pipfile

@@ -0,0 +1,9 @@
+[[source]]
+url = "https://pypi.python.org/simple"
+verify_ssl = true
+name = "pypi"
+
+[dev-packages]
+
+[packages]
+"bob-builder" = "==0.0.13"

Pipfile.lock

@@ -0,0 +1,52 @@
+{
+    "_meta": {
+        "hash": {
+            "sha256": "36d17c46a8b1b844b3cae475f6f42d6c0a9e59b2a9685cbcdc0985656a7a129f"
+        },
+        "host-environment-markers": {
+            "implementation_name": "cpython",
+            "implementation_version": "3.6.3",
+            "os_name": "posix",
+            "platform_machine": "x86_64",
+            "platform_python_implementation": "CPython",
+            "platform_release": "16.7.0",
+            "platform_system": "Darwin",
+            "platform_version": "Darwin Kernel Version 16.7.0: Thu Jun 15 17:36:27 PDT 2017; root:xnu-3789.70.16~2/RELEASE_X86_64",
+            "python_full_version": "3.6.3",
+            "python_version": "3.6",
+            "sys_platform": "darwin"
+        },
+        "pipfile-spec": 6,
+        "requires": {},
+        "sources": [
+            {
+                "name": "pypi",
+                "url": "https://pypi.python.org/simple",
+                "verify_ssl": true
+            }
+        ]
+    },
+    "default": {
+        "bob-builder": {
+            "hashes": [
+                "sha256:b4de49a8e436fcaf82236ea43f78413b4a4c92100726e382ab57b6bdfb38fe64",
+                "sha256:288e3e765c4890fe9a63ae52ac6b4a963c13fe508482c70ff701a5ae21b9a673"
+            ],
+            "version": "==0.0.13"
+        },
+        "boto": {
+            "hashes": [
+                "sha256:13be844158d1bd80a94c972c806ec8381b9ea72035aa06123c5db6bc6a6f3ead",
+                "sha256:deb8925b734b109679e3de65856018996338758f4b916ff4fe7bb62b6d7000d1"
+            ],
+            "version": "==2.48.0"
+        },
+        "docopt": {
+            "hashes": [
+                "sha256:49b3a825280bd66b3aa83585ef59c4a8c82f2c8a522dbe754a8bc8d08c85c491"
+            ],
+            "version": "==0.6.2"
+        }
+    },
+    "develop": {}
+}

README.md

@@ -0,0 +1,88 @@
+![python](https://cloud.githubusercontent.com/assets/51578/13712821/b68a42ce-e793-11e5-96b0-d8eb978137ba.png)
+
+# Heroku Buildpack: Python
+
+[![Build Status](https://travis-ci.org/heroku/heroku-buildpack-python.svg?branch=master)](https://travis-ci.org/heroku/heroku-buildpack-python)
+
+This is the official [Heroku buildpack](https://devcenter.heroku.com/articles/buildpacks) for Python apps.
+
+Recommended web frameworks include **Django** and **Flask**, among others. The recommended webserver is **Gunicorn**. There are no restrictions around what software can be used (as long as it's pip-installable). Web processes must bind to `$PORT`, and only the HTTP protocol is permitted for incoming connections.
+
+Python packages with C dependencies that are not [available on the stack image](https://devcenter.heroku.com/articles/stack-packages) are generally not supported, unless `manylinux` wheels are provided by the package maintainers (common). For recommended solutions, check out [this article](https://devcenter.heroku.com/articles/python-c-deps) for more information.
+
+See it in Action
+----------------
+```
+$ ls
+my-application		requirements.txt	runtime.txt
+
+$ git push heroku master
+Counting objects: 4, done.
+Delta compression using up to 8 threads.
+Compressing objects: 100% (2/2), done.
+Writing objects: 100% (4/4), 276 bytes | 276.00 KiB/s, done.
+Total 4 (delta 0), reused 0 (delta 0)
+remote: Compressing source files... done.
+remote: Building source:
+remote:
+remote: -----> Python app detected
+remote: -----> Installing python-3.7.4
+remote: -----> Installing pip
+remote: -----> Installing SQLite3
+remote: -----> Installing requirements with pip
+remote:        Collecting flask (from -r /tmp/build_c2c067ef79ff14c9bf1aed6796f9ed1f/requirements.txt (line 1))
+remote:          Downloading ...
+remote:        Installing collected packages: Werkzeug, click, MarkupSafe, Jinja2, itsdangerous, flask
+remote:        Successfully installed Jinja2-2.10 MarkupSafe-1.1.0 Werkzeug-0.14.1 click-7.0 flask-1.0.2 itsdangerous-1.1.0
+remote:
+remote: -----> Discovering process types
+remote:        Procfile declares types -> (none)
+remote:
+```
+
+A `requirements.txt` must be present at the root of your application's repository to deploy.
+
+To specify your python version, you also need a `runtime.txt` file - unless you are using the default Python runtime version.
+
+Current default Python Runtime: Python 3.6.9
+
+Alternatively, you can provide a `setup.py` file, or a `Pipfile`. Using `Pipenv` will generate `runtime.txt` based on `python-version` at build time.
+
+Specify a Buildpack Version
+---------------------------
+
+You can specify the latest production release of this buildpack for upcoming builds of an existing application:
+
+    $ heroku buildpacks:set heroku/python
+
+
+Specify a Python Runtime
+------------------------
+
+Supported runtime options include:
+
+- `python-3.7.4`
+- `python-3.6.9`
+- `python-2.7.17`
+
+## Tests
+
+The buildpack tests use [Docker](https://www.docker.com/) to simulate
+Heroku's [stack images.](https://devcenter.heroku.com/articles/stack)
+
+To run the test suite:
+
+```
+make test
+```
+
+Or to test in a particular stack:
+
+```
+make test-heroku-18
+make test-heroku-16
+```
+
+The tests are run via the vendored
+[shunit2](https://github.com/kward/shunit2)
+test framework.

Rakefile

@@ -0,0 +1 @@
+require 'hatchet/tasks'

Readme.md

@@ -1,52 +0,0 @@
-Heroku buildpack: Python
-========================
-
-This is a [Heroku buildpack](http://devcenter.heroku.com/articles/buildpacks) for Python apps, powered by [pip](http://www.pip-installer.org/).
-
-
-Usage
------
-
-Example usage:
-
-    $ ls
-    Procfile  requirements.txt  web.py
-
-    $ heroku create --buildpack git://github.com/heroku/heroku-buildpack-python.git
-
-    $ git push heroku master
-    ...
-    -----> Python app detected
-    -----> Installing runtime (python-2.7.8)
-    -----> Installing dependencies using pip
-           Downloading/unpacking requests (from -r requirements.txt (line 1))
-           Installing collected packages: requests
-           Successfully installed requests
-           Cleaning up...
-    -----> Discovering process types
-           Procfile declares types -> (none)
-
-You can also add it to upcoming builds of an existing application:
-
-    $ heroku config:add BUILDPACK_URL=git://github.com/heroku/heroku-buildpack-python.git
-
-The buildpack will detect your app as Python if it has the file `requirements.txt` in the root.
-
-It will use Pip to install your dependencies, vendoring a copy of the Python runtime into your slug.
-
-Specify a Runtime
------------------
-
-You can also provide arbitrary releases Python with a `runtime.txt` file.
-
-    $ cat runtime.txt
-    python-3.4.2
-
-Runtime options include:
-
-- python-2.7.8
-- python-3.4.2
-- pypy-2.4.0 (unsupported, experimental)
-- pypy3-2.4.0 (unsupported, experimental)
-
-Other [unsupported runtimes](https://github.com/heroku/heroku-buildpack-python/tree/master/builds/runtimes) are available as well.

bin/compile

@@ -1,5 +1,13 @@
 #!/usr/bin/env bash
 
+# The Heroku Python Buildpack. This script accepts parameters for a build
+# directory, a cache directory, and a directory for app environment variables.
+
+# Warning: there are a few hacks in this script to accommodate excellent builds
+# on Heroku. No guarantee for external compatibility is made. However,
+# everything should work fine outside of the Heroku environment, if the
+# environment is setup correctly.
+
 # Usage:
 #
 #     $ bin/compile <build-dir> <cache-dir> <env-path>
@@ -7,211 +15,395 @@
 # Fail fast and fail hard.
 set -eo pipefail
 
-# Prepend proper path for virtualenv hackery. This will be deprecated soon.
+# Boostrap the Buildpack Standard Library.
+export BPLOG_PREFIX="buildpack.python"
+export BUILDPACK_LOG_FILE=${BUILDPACK_LOG_FILE:-/dev/null}
+
+[ "$BUILDPACK_XTRACE" ] && set -o xtrace
+
+# Prepend proper path for old-school virtualenv hackery.
+# This may not be neccessary.
 export PATH=:/usr/local/bin:$PATH
 
-# Paths.
+# Setup Path variables, for later use in the Buildpack.
-BIN_DIR=$(cd $(dirname $0); pwd) # absolute path
+BIN_DIR=$(cd "$(dirname "$0")"; pwd) # absolute path
-ROOT_DIR=$(dirname $BIN_DIR)
+ROOT_DIR=$(dirname "$BIN_DIR")
 BUILD_DIR=$1
 CACHE_DIR=$2
 ENV_DIR=$3
 
+# Export Path variables, for use in sub-scripts.
+export BUILD_DIR CACHE_DIR ENV_DIR
 
-CACHED_DIRS=".heroku"
+# Set the Buildpack's internet target for downloading Python distributions.
+# The user can provide BUILDPACK_VENDOR_URL to specify a custom target.
+# Note: this is designed for non-Heroku use, as it does not use the user-provided
+# environment variable mechanism (the ENV_DIR).
+VENDOR_URL="https://lang-python.s3.amazonaws.com/$STACK"
+if [[ -n ${BUILDPACK_VENDOR_URL:-} ]]; then
+    VENDOR_URL="$BUILDPACK_VENDOR_URL"
+elif [[ -n ${USE_STAGING_BINARIES} ]]; then
+    VENDOR_URL="$USE_STAGING_BINARIES/$STACK"
+fi
+export VENDOR_URL
 
-# Static configurations for virtualenv caches.
+# Default Python Versions
-VIRTUALENV_LOC=".heroku/venv"
+# shellcheck source=bin/default_pythons
-LEGACY_TRIGGER="lib/python2.7"
+source "$BIN_DIR/default_pythons"
-PROFILE_PATH="$BUILD_DIR/.profile.d/python.sh"
-WEBCONCURRENCY_PROFILE_PATH="$BUILD_DIR/.profile.d/python.webconcurrency.sh"
 
-DEFAULT_PYTHON_VERSION="python-2.7.9"
+# Supported Python Branches
-DEFAULT_PYTHON_STACK="cedar"
+PY38="python-3.8"
-PYTHON_EXE="/app/.heroku/python/bin/python"
+PY37="python-3.7"
-PIP_VERSION="6.0.6"
+PY36="python-3.6"
-SETUPTOOLS_VERSION="11.3.1"
+PY35="python-3.5"
+PY34="python-3.4"
+PY27="python-2.7"
+PYPY27="pypy2.7"
+PYPY36="pypy3.6"
 
-# Setup bpwatch
+# Which stack is used (for binary downloading), if none is provided (e.g. outside of Heroku)?
-export PATH=$PATH:$ROOT_DIR/vendor/bpwatch
+DEFAULT_PYTHON_STACK="cedar-14"
-LOGPLEX_KEY="t.b90d9d29-5388-4908-9737-b4576af1d4ce"
+# If pip doesn't match this version (the version we install), run the installer.
-export BPWATCH_STORE_PATH=$CACHE_DIR/bpwatch.json
+PIP_UPDATE="20.0.2"
-BUILDPACK_VERSION=v28
 
-# Setup pip-pop (pip-diff)
+for file in "$BUILD_DIR/runtime.txt" "$CACHE_DIR/.heroku/python-version" ; do
-export PATH=$PATH:$ROOT_DIR/vendor/pip-pop
+    [ -f "$file" ] || continue
 
-# Support Anvil Build_IDs
+    version=$(tr -d '[:space:]' < "$file")
+
+    case "$version" in "$PY34"*)
+        # Python 3.4 support was dropped in pip >= 19.2.
+        PIP_UPDATE="19.1.1"
+        break
+        ;;
+    esac
+done
+
+if [[ -f "$BUILD_DIR/Pipfile" ]]; then
+    # Do not force pipenv users to re-install pipenv locally.
+    PIP_UPDATE="9.0.2"
+fi
+
+export DEFAULT_PYTHON_STACK PIP_UPDATE
+export PY37 PY36 PY35 PY27 PY34
+
+# Common Problem Warnings:
+# This section creates a temporary file in which to stick the output of `pip install`.
+# The `warnings` subscript then greps through this for common problems and guides
+# the user towards resolution of known issues.
+WARNINGS_LOG=$(mktemp)
+export WARNINGS_LOG
+export RECOMMENDED_PYTHON_VERSION=$DEFAULT_PYTHON_VERSION
+
+# The buildpack ships with a few executable tools (e.g. pip-grep, etc).
+# This installs them into the path, so we can execute them directly.
+export PATH=$PATH:$ROOT_DIR/vendor/:$ROOT_DIR/vendor/pip-pop
+
+# Set environment variables if they weren't set by the platform.
+# Note: this is legacy, for a deprecated build system known as Anvil.
+# This can likely be removed, with caution.
 [ ! "$SLUG_ID" ] && SLUG_ID="defaultslug"
 [ ! "$REQUEST_ID" ] && REQUEST_ID=$SLUG_ID
 [ ! "$STACK" ] && STACK=$DEFAULT_PYTHON_STACK
 
-# Sanitizing environment variables.
+# Sanitize externally-provided environment variables:
-unset GIT_DIR PYTHONHOME PYTHONPATH LD_LIBRARY_PATH LIBRARY_PATH
+# The following environment variables are either problematic or simply unneccessary
+# for the buildpack to have knowledge of, so we unset them, to keep the environment
+# as clean and pristine as possible.
+unset GIT_DIR PYTHONHOME PYTHONPATH
+unset RECEIVE_DATA RUN_KEY BUILD_INFO DEPLOY LOG_TOKEN
+unset CYTOKINE_LOG_FILE GEM_PATH
 
-bpwatch init $LOGPLEX_KEY
+# Import the utils script, which contains helper functions used throughout the buildpack.
-bpwatch build python $BUILDPACK_VERSION $REQUEST_ID
+# shellcheck source=bin/utils
-TMP_APP_DIR=$CACHE_DIR/tmp_app_dir
+source "$BIN_DIR/utils"
 
-bpwatch start compile
+# Import the warnings script, which contains the `pip install` user warning mechanisms
+# (mentioned and explained above)
+# shellcheck source=bin/warnings
+source "$BIN_DIR/warnings"
 
+# Make the directory in which we will create symlinks from the temporary build directory
+# to `/app`.
+# Symlinks are required, since Python is not a portable installation.
+# More on this topic later.
+mkdir -p /app/.heroku
+
+# This buildpack programatically generates (or simply copies) a number of files for
+# buildpack machinery: an export script, and a number of `.profile.d` scripts. This
+# section declares the locations of those files and targets.
+PROFILE_PATH="$BUILD_DIR/.profile.d/python.sh"
+EXPORT_PATH="$BIN_DIR/../export"
+GUNICORN_PROFILE_PATH="$BUILD_DIR/.profile.d/python.gunicorn.sh"
+WEB_CONCURRENCY_PROFILE_PATH="$BUILD_DIR/.profile.d/WEB_CONCURRENCY.sh"
 
 # We'll need to send these statics to other scripts we `source`.
-export BUILD_DIR CACHE_DIR BIN_DIR PROFILE_PATH
+export BUILD_DIR CACHE_DIR BIN_DIR PROFILE_PATH EXPORT_PATH
 
-# Syntax sugar.
+# Python Environment Variables
-source $BIN_DIR/utils
+# Set Python-specific environment variables, for running Python within the buildpack.
+# Notes on each variable included.
 
-# Directory Hacks for path consistiency.
+# PATH is relatively obvious, we need to be able to execute 'python'.
-APP_DIR='/app'
+export PATH=/app/.heroku/python/bin:/app/.heroku/vendor/bin:$PATH
-TMP_APP_DIR=$CACHE_DIR/tmp_app_dir
+# Tell Python to not buffer it's stdin/stdout.
-
-# Copy Anvil app dir to temporary storage...
-bpwatch start anvil_appdir_stage
-  if [ "$SLUG_ID" ]; then
-    mkdir -p $TMP_APP_DIR
-    deep-mv $APP_DIR $TMP_APP_DIR
-  else
-    deep-rm $APP_DIR
-  fi
-bpwatch stop anvil_appdir_stage
-
-# Copy Application code in.
-bpwatch start appdir_stage
-  deep-mv $BUILD_DIR $APP_DIR
-bpwatch stop appdir_stage
-
-# Set new context.
-ORIG_BUILD_DIR=$BUILD_DIR
-BUILD_DIR=$APP_DIR
-
-# Prepend proper path buildpack use.
-export PATH=$BUILD_DIR/.heroku/python/bin:$BUILD_DIR/.heroku/vendor/bin:$PATH
 export PYTHONUNBUFFERED=1
+# Set the locale to a well-known and expected standard.
 export LANG=en_US.UTF-8
-export C_INCLUDE_PATH=/app/.heroku/vendor/include:$BUILD_DIR/.heroku/vendor/include:/app/.heroku/python/include
+# `~/.heroku/vendor` is an place where the buildpack may stick pre-build binaries for known
-export CPLUS_INCLUDE_PATH=/app/.heroku/vendor/include:$BUILD_DIR/.heroku/vendor/include:/app/.heroku/python/include
+# C dependencies (e.g. libmemcached on cedar-14). This section configures Python (GCC, more specifically)
-export LIBRARY_PATH=/app/.heroku/vendor/lib:$BUILD_DIR/.heroku/vendor/lib:/app/.heroku/python/lib
+# and pip to automatically include these paths when building binaries.
-export LD_LIBRARY_PATH=/app/.heroku/vendor/lib:$BUILD_DIR/.heroku/vendor/lib:/app/.heroku/python/lib
+export C_INCLUDE_PATH=/app/.heroku/vendor/include:/app/.heroku/python/include:$C_INCLUDE_PATH
-export PKG_CONFIG_PATH=/app/.heroku/vendor/lib/pkg-config:$BUILD_DIR/.heroku/vendor/lib/pkg-config:/app/.heroku/python/lib/pkg-config
+export CPLUS_INCLUDE_PATH=/app/.heroku/vendor/include:/app/.heroku/python/include:$CPLUS_INCLUDE_PATH
+export LIBRARY_PATH=/app/.heroku/vendor/lib:/app/.heroku/python/lib:$LIBRARY_PATH
+export LD_LIBRARY_PATH=/app/.heroku/vendor/lib:/app/.heroku/python/lib:$LD_LIBRARY_PATH
+export PKG_CONFIG_PATH=/app/.heroku/vendor/lib/pkg-config:/app/.heroku/python/lib/pkg-config:$PKG_CONFIG_PATH
+
+# The Application Code
+# --------------------
 
 # Switch to the repo's context.
-cd $BUILD_DIR
+cd "$BUILD_DIR"
 
-# Experimental pre_compile hook.
+# The Cache
-bpwatch start pre_compile
+# ---------
-  source $BIN_DIR/steps/hooks/pre_compile
-bpwatch stop pre_compile
 
-# If no requirements given, assume `setup.py develop`.
+# The workflow for the Python Buildpack's cache is as follows:
-if [ ! -f requirements.txt ]; then
+#
+# - `~/.heroku/{known-paths}` are copied from the cache into the slug.
+# - The build is executed, modifying `~/.heroku/{known-paths}`.
+# - Once the build is complete, `~/.heroku/{known-paths}` is copied back into the cache.
+
+# Create the cache directory, if it doesn't exist.
+mkdir -p "$CACHE_DIR"
+
+# Restore old artifacts from the cache.
+mkdir -p .heroku
+
+# The Python installation.
+cp -R "$CACHE_DIR/.heroku/python" .heroku/ &> /dev/null || true
+# A plain text file which contains the current stack being used (used for cache busting).
+cp -R "$CACHE_DIR/.heroku/python-stack" .heroku/ &> /dev/null || true
+# A plain text file which contains the current python version being used (used for cache busting).
+cp -R "$CACHE_DIR/.heroku/python-version" .heroku/ &> /dev/null || true
+# A plain text file which contains the current sqlite3 version being used (used for cache busting).
+cp -R "$CACHE_DIR/.heroku/python-sqlite3-version" .heroku/ &> /dev/null || true
+# Any pre-compiled binaries, provided by the buildpack.
+cp -R "$CACHE_DIR/.heroku/vendor" .heroku/ &> /dev/null || true
+# "editable" installations of code repositories, via pip or pipenv.
+if [[ -d "$CACHE_DIR/.heroku/src" ]]; then
+  cp -R "$CACHE_DIR/.heroku/src" .heroku/ &> /dev/null || true
+fi
+
+# The pre_compile hook. Customers rely on this. Don't remove it.
+# This part of the code is used to allow users to customize their build experience
+# without forking the buildpack by providing a `bin/pre_compile` script, which gets
+# run inline with the buildpack automatically.
+
+# shellcheck source=bin/steps/hooks/pre_compile
+source "$BIN_DIR/steps/hooks/pre_compile"
+
+# Sticky runtimes. If there was a previous build, and it used a given version of Python,
+# continue to use that version of Python in perpituity (warnings will be raised if
+# they are out–of–date).
+if [ -f "$CACHE_DIR/.heroku/python-version" ]; then
+  DEFAULT_PYTHON_VERSION=$(cat "$CACHE_DIR/.heroku/python-version")
+fi
+
+# We didn't always record the stack version. This code is in place because of that.
+if [ -f "$CACHE_DIR/.heroku/python-stack" ]; then
+  CACHED_PYTHON_STACK=$(cat "$CACHE_DIR/.heroku/python-stack")
+else
+  CACHED_PYTHON_STACK=$STACK
+fi
+
+export CACHED_PYTHON_STACK
+
+# Pipenv Python version support.
+# Detect the version of Python requested from a Pipfile (e.g. python_version or python_full_version).
+# Convert it to a runtime.txt file.
+
+# shellcheck source=bin/steps/pipenv-python-version
+source "$BIN_DIR/steps/pipenv-python-version"
+
+# If no runtime was provided by the user, assume the default Python runtime version.
+if [ ! -f runtime.txt ]; then
+  echo "$DEFAULT_PYTHON_VERSION" > runtime.txt
+fi
+
+# Create the directory for .profile.d, if it doesn't exist.
+mkdir -p "$(dirname "$PROFILE_PATH")"
+# Create the directory for editable source code installation, if it doesn't exist.
+mkdir -p /app/.heroku/src
+
+# On Heroku CI, builds happen in `/app`. Otherwise, on the Heroku platform,
+# they occur in a temp directory. Beacuse Python is not portable, we must create
+# symlinks to emulate that we are operating in `/app` during the build process.
+# This is (hopefully obviously) because apps end up running from `/app` in production.
+if [[ $BUILD_DIR != '/app' ]]; then
+    # python expects to reside in /app, so set up symlinks
+    # we will not remove these later so subsequent buildpacks can still invoke it
+    ln -nsf "$BUILD_DIR/.heroku/python" /app/.heroku/python
+    ln -nsf "$BUILD_DIR/.heroku/vendor" /app/.heroku/vendor
+    # Note: .heroku/src is copied in later.
+fi
+
+# Download / Install Python, from pre-build binaries available on Amazon S3.
+# This step also bootstraps pip / setuptools.
+(( start=$(nowms) ))
+# shellcheck source=bin/steps/python
+source "$BIN_DIR/steps/python"
+mtime "python.install.time" "${start}"
+
+# Install Pipenv dependencies, if a Pipfile was provided.
+# shellcheck source=bin/steps/pipenv
+source "$BIN_DIR/steps/pipenv"
+
+# Uninstall removed dependencies with Pip.
+# The buildpack will automatically remove any declared dependencies (in requirements.txt)
+# that were explicitly removed. This machinery is a bit complex, but it is not complicated.
+(( start=$(nowms) ))
+# shellcheck source=bin/steps/pip-uninstall
+source "$BIN_DIR/steps/pip-uninstall"
+mtime "pip.uninstall.time" "${start}"
+
+# If no requirements.txt file given, assume `setup.py develop` is intended.
+# This allows for people to ship a setup.py application to Heroku
+# (which is rare, but I vouch that it should work!)
+
+if [ ! -f requirements.txt ] && [ ! -f Pipfile ]; then
   echo "-e ." > requirements.txt
 fi
 
-# Sticky runtimes.
+# Fix egg-links.
-if [ -f $CACHE_DIR/.heroku/python-version ]; then
+# Because we're installing things into a different path than we're running them (temp dir vs app dir),
-  DEFAULT_PYTHON_VERSION=$(cat $CACHE_DIR/.heroku/python-version)
+# We must re-write all of Python's eggpath links to target the proper directory.
-fi
+# shellcheck source=bin/steps/eggpath-fix
-
+source "$BIN_DIR/steps/eggpath-fix"
-# Stack fallback for non-declared caches.
-if [ -f $CACHE_DIR/.heroku/python-stack ]; then
-  CACHED_PYTHON_STACK=$(cat $CACHE_DIR/.heroku/python-stack)
-else
-  CACHED_PYTHON_STACK=$DEFAULT_PYTHON_STACK
-fi
-
-# If no runtime given, assume default version.
-if [ ! -f runtime.txt ]; then
-  echo $DEFAULT_PYTHON_VERSION > runtime.txt
-fi
-
-# ### The Cache
-mkdir -p $CACHE_DIR
-
-# Purge "old-style" virtualenvs.
-bpwatch start clear_old_venvs
-  [ -d $CACHE_DIR/$LEGACY_TRIGGER ] && rm -fr $CACHE_DIR/.heroku/bin $CACHE_DIR/.heroku/lib $CACHE_DIR/.heroku/include
-  [ -d $CACHE_DIR/$VIRTUALENV_LOC ] && rm -fr $CACHE_DIR/.heroku/venv $CACHE_DIR/.heroku/src
-bpwatch stop clear_old_venvs
-
-# Restore old artifacts from the cache.
-bpwatch start restore_cache
-  for dir in $CACHED_DIRS; do
-    cp -R $CACHE_DIR/$dir . &> /dev/null || true
-  done
-bpwatch stop restore_cache
-
-set +e
-# Create set-aside `.heroku` folder.
-mkdir .heroku &> /dev/null
-set -e
-
-mkdir -p $(dirname $PROFILE_PATH)
-
-# Install Python.
-source $BIN_DIR/steps/python
-
-# Sanity check for setuptools/distribute.
-source $BIN_DIR/steps/setuptools
-
-# Uninstall removed dependencies with Pip.
-source $BIN_DIR/steps/pip-uninstall
 
 # Mercurial support.
-source $BIN_DIR/steps/mercurial
+# If a customer appears to be using mercurial for dependency resolution, we install it first.
+# Note: this only applies to pip, not pipenv. This can likely be removed, over time. Measure it first.
+# shellcheck source=bin/steps/mercurial
+source "$BIN_DIR/steps/mercurial"
 
 # Pylibmc support.
-source $BIN_DIR/steps/pylibmc
+# On cedar-14, libmemcached was not available. The buildpack provides its own version, instead.
+# shellcheck source=bin/steps/pylibmc
+source "$BIN_DIR/steps/pylibmc"
 
-# Libffi support.
+# Support for Geo libraries. This is deprecated functionality, only functional on cedar-14.
-source $BIN_DIR/steps/cryptography
+# It is undocumented.
+# shellcheck source=bin/steps/geo-libs
+sub_env "$BIN_DIR/steps/geo-libs"
+
+# GDAL support.
+# This is part of the Geo support.
+# shellcheck source=bin/steps/gdal
+source "$BIN_DIR/steps/gdal"
+
+# SQLite3 support.
+# This sets up and installs sqlite3 dev headers and the sqlite3 binary but not the
+# libsqlite3-0 library since that exists on the stack image.
+# Note: This only applies to Python 2.7.15+ and Python 3.6.6+
+(( start=$(nowms) ))
+# shellcheck source=bin/steps/sqlite3
+source "$BIN_DIR/steps/sqlite3"
+buildpack_sqlite3_install
+mtime "sqlite3.install.time" "${start}"
+
+# pip install
+# -----------
+
+# Install dependencies with pip (where the magic happens).
+(( start=$(nowms) ))
+# shellcheck source=bin/steps/pip-install
+source "$BIN_DIR/steps/pip-install"
+mtime "pip.install.time" "${start}"
+
+# Support for NLTK corpora.
+# Note: this may only work on Python 2.7. I don't think many customers use this functionality,
+# and it should probably be undocumented.
+# (there's an import error on 3.6 that should hopefully be fixed upstream at some point)
+(( start=$(nowms) ))
+sub_env "$BIN_DIR/steps/nltk"
+mtime "nltk.download.time" "${start}"
+
+# Support for editable installations. Here, we are copying pip–created src directory,
+# and copying it into the proper place (the logical place to do this was early, but it must be done here).
+# In CI, $BUILD_DIR is /app.
+if [[ ! "$BUILD_DIR" == "/app" ]]; then
+  rm -fr "$BUILD_DIR/.heroku/src"
+  deep-cp /app/.heroku/src "$BUILD_DIR/.heroku/src"
+fi
 
-# Install dependencies with Pip.
-sub-env $BIN_DIR/steps/pip-install
 
 # Django collectstatic support.
-sub-env $BIN_DIR/steps/collectstatic
+# The buildpack automatically runs collectstatic for Django applications.
+# This is the cause for the majority of build failures on the Python platform.
+# These failures are intentional — if collectstatic (which can be tricky, at times) fails,
+# your build fails.
+(( start=$(nowms) ))
+sub_env "$BIN_DIR/steps/collectstatic"
+mtime "collectstatic.time" "${start}"
 
 
-# ### Finalize
+# Progamatically create .profile.d script for application runtime environment variables.
-#
 
-# Set context environment variables.
+# Set the PATH to include Python / pip / pipenv / etc.
-set-env PATH '$HOME/.heroku/python/bin:$PATH'
+set_env PATH "\$HOME/.heroku/python/bin:\$PATH"
-set-env PYTHONUNBUFFERED true
+# Tell Python to run in unbuffered mode.
-set-env PYTHONHOME /app/.heroku/python
+set_env PYTHONUNBUFFERED true
-set-env LIBRARY_PATH /app/.heroku/vendor/lib:/app/.heroku/python/lib
+# Tell Python where it lives.
-set-env LD_LIBRARY_PATH '/app/.heroku/vendor/lib:/app/.heroku/python/lib:$LD_LIBRARY_PATH'
+set_env PYTHONHOME "\$HOME/.heroku/python"
-set-default-env LANG en_US.UTF-8
+# Set variables for C libraries.
-set-default-env PYTHONHASHSEED random
+set_env LIBRARY_PATH "\$HOME/.heroku/vendor/lib:\$HOME/.heroku/python/lib:\$LIBRARY_PATH"
-set-default-env PYTHONPATH /app/
+set_env LD_LIBRARY_PATH "\$HOME/.heroku/vendor/lib:\$HOME/.heroku/python/lib:\$LD_LIBRARY_PATH"
+# Locale.
+set_default_env LANG en_US.UTF-8
+# The Python hash seed is set to random.
+set_default_env PYTHONHASHSEED random
+# Tell Python to look for Python modules in the /app dir. Don't change this.
+set_default_env PYTHONPATH "\$HOME"
 
-# Install sane-default script for WEB_CONCURRENCY environment variable.
+# Python expects to be in /app, if at runtime, it is not, set
-cp $ROOT_DIR/vendor/python.webconcurrency.sh $WEBCONCURRENCY_PROFILE_PATH
+# up symlinks… this can occur when the subdir buildpack is used.
+cat <<EOT >> "$PROFILE_PATH"
+if [[ \$HOME != "/app" ]]; then
+    mkdir -p /app/.heroku
+    ln -nsf "\$HOME/.heroku/python" /app/.heroku/python
+    ln -nsf "\$HOME/.heroku/vendor" /app/.heroku/vendor
+fi
+EOT
 
+# Install sane-default script for $WEB_CONCURRENCY and $FORWARDED_ALLOW_IPS.
+cp "$ROOT_DIR/vendor/WEB_CONCURRENCY.sh" "$WEB_CONCURRENCY_PROFILE_PATH"
+cp "$ROOT_DIR/vendor/python.gunicorn.sh" "$GUNICORN_PROFILE_PATH"
 
-# Experimental post_compile hook.
+# Experimental post_compile hook. Don't remove this.
-bpwatch start post_compile
+# shellcheck source=bin/steps/hooks/post_compile
-  source $BIN_DIR/steps/hooks/post_compile
+source "$BIN_DIR/steps/hooks/post_compile"
-bpwatch stop post_compile
 
-# Store new artifacts in cache.
+# Fix egg-links, again.
-bpwatch start dump_cache
+# shellcheck source=bin/steps/eggpath-fix2
-  for dir in $CACHED_DIRS; do
+source "$BIN_DIR/steps/eggpath-fix2"
-    rm -rf $CACHE_DIR/$dir
-    cp -R $dir $CACHE_DIR/
-  done
-bpwatch stop dump_cache
 
-# ### Fin.
+# Store new artifacts in the cache.
-bpwatch start appdir_commit
+rm -rf "$CACHE_DIR/.heroku/python"
-  deep-mv $BUILD_DIR $ORIG_BUILD_DIR
+rm -rf "$CACHE_DIR/.heroku/python-version"
-bpwatch stop appdir_commit
+rm -rf "$CACHE_DIR/.heroku/python-stack"
+rm -rf "$CACHE_DIR/.heroku/vendor"
+rm -rf "$CACHE_DIR/.heroku/src"
 
-bpwatch start anvil_appdir_commit
+mkdir -p "$CACHE_DIR/.heroku"
-  if [ "$SLUG_ID" ]; then
+cp -R .heroku/python "$CACHE_DIR/.heroku/"
-    deep-mv $TMP_APP_DIR $APP_DIR
+cp -R .heroku/python-version "$CACHE_DIR/.heroku/"
-  fi
+cp -R .heroku/python-stack "$CACHE_DIR/.heroku/" &> /dev/null || true
+cp -R .heroku/vendor "$CACHE_DIR/.heroku/" &> /dev/null || true
+if [[ -d .heroku/src ]]; then
+  cp -R .heroku/src "$CACHE_DIR/.heroku/" &> /dev/null || true
+fi
 
-bpwatch stop anvil_appdir_commit
+# Measure the size of the Python installation.
-bpwatch stop compile
+# shellcheck disable=SC2119
+mmeasure 'python.size' "$(measure-size)"

bin/default_pythons

@@ -0,0 +1,21 @@
+#!/usr/bin/env bash
+
+DEFAULT_PYTHON_VERSION="python-3.6.10"
+LATEST_38="python-3.8.2"
+LATEST_37="python-3.7.6"
+LATEST_36="python-3.6.10"
+LATEST_35="python-3.5.7"
+LATEST_34="python-3.4.10"
+LATEST_27="python-2.7.17"
+PYPY_36="pypy3.6-7.2.0"
+PYPY_27="pypy2.7-7.2.0"
+
+export DEFAULT_PYTHON_VERSION \
+    LATEST_38 \
+    LATEST_37 \
+    LATEST_36 \
+    LATEST_35 \
+    LATEST_34 \
+    LATEST_27 \
+    PYPY_36 \
+    PYPY_27

bin/detect

@@ -4,7 +4,7 @@
 # [**Python Buildpack**](https://github.com/heroku/heroku-buildpack-python)
 # detector.
 #
-# A [buildpack](http://devcenter.heroku.com/articles/buildpacks) is an
+# A [buildpack](https://devcenter.heroku.com/articles/buildpacks) is an
 # adapter between a Python application and Heroku's runtime.
 
 # ## Usage
@@ -15,7 +15,7 @@
 BUILD_DIR=$1
 
 # Exit early if app is clearly not Python.
-if [ ! -f $BUILD_DIR/requirements.txt ] && [ ! -f $BUILD_DIR/setup.py ]; then
+if [ ! -f "$BUILD_DIR/requirements.txt" ] && [ ! -f "$BUILD_DIR/setup.py" ] && [ ! -f "$BUILD_DIR/Pipfile" ]; then
   exit 1
 fi
 

bin/release

@@ -1,10 +1,9 @@
 #!/usr/bin/env bash
 # bin/release <build-dir>
 
-BIN_DIR=$(cd $(dirname $0); pwd) # absolute path
 BUILD_DIR=$1
 
-MANAGE_FILE=$(cd $BUILD_DIR && find . -maxdepth 3 -type f -name 'manage.py' | head -1)
+MANAGE_FILE=$(cd "$BUILD_DIR" && find . -maxdepth 3 -type f -name 'manage.py' | head -1)
 MANAGE_FILE=${MANAGE_FILE:2}
 
 cat <<EOF
@@ -18,6 +17,6 @@ if [[ $MANAGE_FILE ]]; then
 cat <<EOF
 
 addons:
-  heroku-postgresql:hobby-dev
+  - heroku-postgresql
 EOF
 fi

bin/steps/collectstatic

@@ -1,36 +1,87 @@
 #!/usr/bin/env bash
 
-source $BIN_DIR/utils
+# Django Collectstatic runner. If you have Django installed, collectstatic will
+# automatically be executed as part of the build process. If collectstatic
+# fails, your build fails.
 
-MANAGE_FILE=$(find . -maxdepth 3 -type f -name 'manage.py' | head -1)
+# This functionality will only activate if Django is in requirements.txt.
+
+# Runtime arguments:
+#   - $DISABLE_COLLECTSTATIC: disables this functionality.
+#   - $DEBUG_COLLECTSTATIC: upon failure, print out environment variables.
+
+# shellcheck source=bin/utils
+source "$BIN_DIR/utils"
+
+# Location of 'manage.py', if it exists.
+MANAGE_FILE=$(find . -maxdepth 3 -type f -name 'manage.py' -printf '%d\t%P\n' | sort -nk1 | cut -f2 | head -1)
 MANAGE_FILE=${MANAGE_FILE:-fakepath}
 
+# Legacy file-based support for $DISABLE_COLLECTSTATIC
 [ -f .heroku/collectstatic_disabled ] && DISABLE_COLLECTSTATIC=1
 
-bpwatch start collectstatic
+# Ensure that Django is explicitly specified in requirements.txt
+sp-grep -s django && DJANGO_INSTALLED=1
 
-if [ ! "$DISABLE_COLLECTSTATIC" ] && [ -f "$MANAGE_FILE" ]; then
+
+if [ ! "$DISABLE_COLLECTSTATIC" ] && [ -f "$MANAGE_FILE" ] && [ "$DJANGO_INSTALLED" ]; then
     set +e
 
-    echo "-----> Preparing static assets"
+    puts-step "$ python $MANAGE_FILE collectstatic --noinput"
-    # Check if collectstatic is configured properly.
-    python $MANAGE_FILE collectstatic --dry-run --noinput &> /dev/null && RUN_COLLECTSTATIC=true
 
-    # Compile assets if collectstatic appears to be kosher.
+    # Run collectstatic, cleanup some of the noisy output.
-    if [ "$RUN_COLLECTSTATIC" ]; then
+    PYTHONPATH=${PYTHONPATH:-.}
+    export PYTHONPATH
 
-        echo "       Running collectstatic..."
+    # Create a temporary file for collecting the collectstaic logs.
-        python $MANAGE_FILE collectstatic --noinput  2>&1 | sed '/^Copying/d;/^$/d;/^ /d' | indent
+    COLLECTSTATIC_LOG=$(mktemp)
+
+    python "$MANAGE_FILE" collectstatic --noinput --traceback 2>&1 | tee "$COLLECTSTATIC_LOG" | sed '/^Post-processed/d;/^Copying/d;/^$/d' | indent
+    COLLECTSTATIC_STATUS="${PIPESTATUS[0]}"
+
+    set -e
+
+    # Display a warning if collectstatic failed.
+    [ "$COLLECTSTATIC_STATUS" -ne 0 ] && {
+
+        if grep -q 'SyntaxError' "$COLLECTSTATIC_LOG"; then
+            mcount "failure.collectstatic.syntax-error"
+
+        elif grep -q 'ImproperlyConfigured' "$COLLECTSTATIC_LOG"; then
+            mcount "failure.collectstatic.improper-configuration"
+
+        elif grep -q 'The CSS file' "$COLLECTSTATIC_LOG"; then
+            mcount "failure.collectstatic.fancy-references"
+
+        elif grep -q 'OSError' "$COLLECTSTATIC_LOG"; then
+            mcount "failure.collectstatic.missing-file"
+
+        else
+            mcount "failure.collectstatic.other"
+        fi
+
+        echo
+        echo " !     Error while running '$ python $MANAGE_FILE collectstatic --noinput'."
+        echo "       See traceback above for details."
+        echo
+        echo "       You may need to update application code to resolve this error."
+        echo "       Or, you can disable collectstatic for this application:"
+        echo
+        echo "          $ heroku config:set DISABLE_COLLECTSTATIC=1"
+        echo
+        echo "       https://devcenter.heroku.com/articles/django-assets"
+
+        # Additionally, dump out the environment, if debug mode is on.
+        if [ "$DEBUG_COLLECTSTATIC" ]; then
+            echo
+            echo "****** Collectstatic environment variables:"
+            echo
+            env | indent
+        fi
+
+        # Abort the build.
+        exit 1
+    }
 
-        [ $? -ne 0 ] && {
-            echo " !     Error running 'manage.py collectstatic'. More info:"
-            echo "       http://devcenter.heroku.com/articles/django-assets"
-        }
-    else
-        echo "       Collectstatic configuration error. To debug, run:"
-        echo "       $ heroku run python $MANAGE_FILE collectstatic --noinput"
-    fi
     echo
 fi
-
-bpwatch stop collectstatic

bin/steps/cryptography

@@ -1,37 +0,0 @@
-#!/usr/bin/env bash
-
-# This script serves as the Pylibmc build step of the
-# [**Python Buildpack**](https://github.com/heroku/heroku-buildpack-python)
-# compiler.
-#
-# A [buildpack](http://devcenter.heroku.com/articles/buildpacks) is an
-# adapter between a Python application and Heroku's runtime.
-#
-# This script is invoked by [`bin/compile`](/).
-
-# The location of the pre-compiled cryptography binary.
-VENDORED_LIBFFI="http://lang-python.s3.amazonaws.com/$STACK/libraries/vendor/libffi.tar.gz"
-
-PKG_CONFIG_PATH="/app/.heroku/vendor/lib/pkgconfig:$PKG_CONFIG_PATH"
-
-# Syntax sugar.
-source $BIN_DIR/utils
-
-bpwatch start libffi_install
-
-# If pylibmc exists within requirements, use vendored cryptography.
-if (pip-grep -s requirements.txt bcrypt cffi cryptography &> /dev/null) then
-
-  if [ -d ".heroku/vendor/lib/libffi-3.1.1" ]; then
-    export LIBFFI=$(pwd)/vendor
-  else
-    echo "-----> Noticed cffi. Bootstrapping libffi."
-    mkdir -p .heroku/vendor
-    # Download and extract cryptography into target vendor directory.
-    curl $VENDORED_LIBFFI -s | tar zxv -C .heroku/vendor &> /dev/null
-
-    export LIBFFI=$(pwd)/vendor
-  fi
-fi
-
-bpwatch stop libffi_install

bin/steps/eggpath-fix

@@ -0,0 +1,13 @@
+#!/usr/bin/env bash
+
+set +e
+# delete any existing egg links, to uninstall exisisting installations.
+find .heroku/python/lib/python*/site-packages/ -name "*.egg-link" -delete 2> /dev/null
+find .heroku/python/lib/python*/site-packages/ -name "*.pth" -print0 2> /dev/null | xargs -r -0 -n 1 sed -i -e "s#/app/#/$(pwd)/#" &> /dev/null
+set -e
+
+set +e
+# Support for the above, for PyPy.
+find .heroku/python/lib-python/*/site-packages/ -name "*.egg-link" -print0 2> /dev/null | xargs -r -0 -n 1 sed -i -e "s#/app/#$(pwd)/#" &> /dev/null
+find .heroku/python/lib-python/*/site-packages/ -name "*.pth" -print0 2> /dev/null | xargs -r -0 -n 1 sed -i -e "s#/app/#/$(pwd)/#" &> /dev/null
+set -e

bin/steps/eggpath-fix2

@@ -0,0 +1,10 @@
+#!/usr/bin/env bash
+set +e
+# rewrite build dir in egg links to /app so things are found at runtime
+find .heroku/python/lib/python*/site-packages/ -name "*.pth" -print0 2> /dev/null | xargs -r -0 -n 1 sed -i -e "s#$(pwd)#/app#" &> /dev/null
+set -e
+
+set +e
+# Support for PyPy
+find .heroku/python/lib-python/*/site-packages/  -name "*.pth" -print0 2> /dev/null | xargs -r -0 -n 1 sed -i -e "s#$(pwd)#/app#" &> /dev/null
+set -e

bin/steps/gdal

@@ -0,0 +1,34 @@
+#!/usr/bin/env bash
+
+# This script serves as the GDAL build step of the
+# [**Python Buildpack**](https://github.com/heroku/heroku-buildpack-python)
+# compiler.
+#
+# A [buildpack](https://devcenter.heroku.com/articles/buildpacks) is an
+# adapter between a Python application and Heroku's runtime.
+#
+# This script is invoked by [`bin/compile`](/).
+
+# The location of the pre-compiled cryptography binary.
+VENDORED_GDAL="${VENDOR_URL}/libraries/vendor/gdal.tar.gz"
+
+PKG_CONFIG_PATH="/app/.heroku/vendor/lib/pkgconfig:$PKG_CONFIG_PATH"
+
+# Syntax sugar.
+# shellcheck source=bin/utils
+source "$BIN_DIR/utils"
+
+# If GDAL exists within requirements, use vendored gdal.
+if (pip-grep -s requirements.txt GDAL gdal pygdal &> /dev/null) then
+
+  if [ ! -f ".heroku/vendor/bin/gdalserver" ]; then
+    echo "-----> Noticed GDAL. Bootstrapping gdal."
+    mkdir -p .heroku/vendor
+    # Download and extract cryptography into target vendor directory.
+    curl "$VENDORED_GDAL" -s | tar zxv -C .heroku/vendor &> /dev/null
+    mcount "steps.vendor.gdal"
+  fi
+
+  GDAL=$(pwd)/vendor
+  export GDAL
+fi

bin/steps/geo-libs

@@ -0,0 +1,52 @@
+#!/usr/bin/env bash
+
+# This script serves as the GDAL build step of the
+# [**Python Buildpack**](https://github.com/heroku/heroku-buildpack-python)
+# compiler.
+#
+# A [buildpack](https://devcenter.heroku.com/articles/buildpacks) is an
+# adapter between a Python application and Heroku's runtime.
+#
+# This script is invoked by [`bin/compile`](/).
+
+# The location of the pre-compiled cryptography binary.
+VENDORED_GDAL="${VENDOR_URL}/libraries/vendor/gdal.tar.gz"
+VENDORED_GEOS="${VENDOR_URL}/libraries/vendor/geos.tar.gz"
+VENDORED_PROJ="${VENDOR_URL}/libraries/vendor/proj.tar.gz"
+
+PKG_CONFIG_PATH="/app/.heroku/vendor/lib/pkgconfig:$PKG_CONFIG_PATH"
+
+# Syntax sugar.
+# shellcheck source=bin/utils
+source "$BIN_DIR/utils"
+
+# If GDAL exists within requirements, use vendored gdal.
+if [[ "$BUILD_WITH_GEO_LIBRARIES" ]]; then
+  mcount "buildvar.BUILD_WITH_GEO_LIBRARIES"
+
+  if [ ! -f ".heroku/vendor/bin/proj" ]; then
+    echo "-----> Bootstrapping gdal, geos, proj."
+    mkdir -p .heroku/vendor
+    # Download and extract cryptography into target vendor directory.
+    curl "$VENDORED_GDAL" -s | tar zxv -C .heroku/vendor &> /dev/null
+    curl "$VENDORED_GEOS" -s | tar zxv -C .heroku/vendor &> /dev/null
+    curl "$VENDORED_PROJ" -s | tar zxv -C .heroku/vendor &> /dev/null
+
+    mcount "steps.vendor.geo_libs"
+    # Copy libjasper from build image to slug.
+    if [[ "$STACK" == "heroku-16" ]]; then
+      cp /usr/lib/x86_64-linux-gnu/libjasper.so* ".heroku/vendor/lib/."
+      mcount "steps.vendor.libjasper"
+    fi
+
+  fi
+
+  GDAL=$(pwd)/vendor
+  export GDAL
+  # set path for post_compile hooks
+  export GDAL_LIBRARY_PATH="$BUILD_DIR/.heroku/vendor/lib/libgdal.so"
+  export GEOS_LIBRARY_PATH="$BUILD_DIR/.heroku/vendor/lib/libgeos_c.so"
+  # set path for runtime environmeht
+  set_env GDAL_LIBRARY_PATH "/app/.heroku/vendor/lib/libgdal.so"
+  set_env GEOS_LIBRARY_PATH "/app/.heroku/vendor/lib/libgeos_c.so"
+fi

bin/steps/hooks/post_compile

@@ -3,5 +3,5 @@
 if [ -f bin/post_compile ]; then
     echo "-----> Running post-compile hook"
     chmod +x bin/post_compile
-    sub-env bin/post_compile
+    sub_env bin/post_compile
 fi

bin/steps/hooks/pre_compile

@@ -3,5 +3,5 @@
 if [ -f bin/pre_compile ]; then
     echo "-----> Running pre-compile hook"
     chmod +x bin/pre_compile
-    sub-env bin/pre_compile
+    sub_env bin/pre_compile
 fi

bin/steps/mercurial

@@ -1,6 +1,9 @@
+#!/usr/bin/env bash
+
 # Install Mercurial if it appears to be required.
-if (grep -Fiq "hg+" requirements.txt) then
+if [[ -f "requirements.txt" ]]; then
-  bpwatch start mercurial_install
+	if (grep -Fiq "hg+" requirements.txt) then
-    /app/.heroku/python/bin/pip install  mercurial | cleanup | indent
+		/app/.heroku/python/bin/pip install  mercurial | cleanup | indent
-  bpwatch stop mercurial_install
+		mcount "steps.mercurial"
-fi
+	fi
+fi

bin/steps/nltk

@@ -0,0 +1,36 @@
+#!/usr/bin/env bash
+
+# This script serves as the NLTK build step of the
+# [**Python Buildpack**](https://github.com/heroku/heroku-buildpack-python)
+# compiler.
+#
+# A [buildpack](https://devcenter.heroku.com/articles/buildpacks) is an
+# adapter between a Python application and Heroku's runtime.
+#
+# This script is invoked by [`bin/compile`](/).
+
+# Syntax sugar.
+# shellcheck source=bin/utils
+source "$BIN_DIR/utils"
+
+# Check that nltk was installed by pip, otherwise obviously not needed
+if sp-grep -s nltk; then
+    puts-step "Downloading NLTK corpora…"
+
+    nltk_packages_definition="$BUILD_DIR/nltk.txt"
+
+    if [ -f "$nltk_packages_definition" ]; then
+
+        readarray -t nltk_packages < "$nltk_packages_definition"
+        puts-step "Downloading NLTK packages: ${nltk_packages[*]}"
+
+        python -m nltk.downloader -d "$BUILD_DIR/.heroku/python/nltk_data" "${nltk_packages[@]}" | indent
+        set_env NLTK_DATA "/app/.heroku/python/nltk_data"
+
+        mcount "buildvar.NLTK_PACKAGES_DEFINITION"
+        mcount "steps.nltk"
+    else
+        puts-warn "'nltk.txt' not found, not downloading any corpora"
+        puts-warn "Learn more: https://devcenter.heroku.com/articles/python-nltk"
+    fi
+fi

bin/steps/pip-install

@@ -1,20 +1,68 @@
 #!/usr/bin/env bash
 
-source $BIN_DIR/utils
+# shellcheck source=bin/utils
+source "$BIN_DIR/utils"
 
-# Install dependencies with Pip.
+if [ ! "$SKIP_PIP_INSTALL" ]; then
-puts-step "Installing dependencies with pip"
 
-[ ! "$FRESH_PYTHON" ] && bpwatch start pip_install
+    # Install dependencies with Pip.
-[ "$FRESH_PYTHON" ] && bpwatch start pip_install_first
+    puts-step "Installing requirements with pip"
 
-/app/.heroku/python/bin/pip install -r requirements.txt --exists-action=w --src=./.heroku/src --allow-all-external  | cleanup | indent
+    # Set Pip env vars
+    # This reads certain environment variables set on the Heroku app config
+    # and makes them accessible to the pip install process.
+    #
+    # PIP_EXTRA_INDEX_URL allows for an alternate pypi URL to be used.
+    if [[ -r "$ENV_DIR/PIP_EXTRA_INDEX_URL" ]]; then
+        PIP_EXTRA_INDEX_URL="$(cat "$ENV_DIR/PIP_EXTRA_INDEX_URL")"
+        export PIP_EXTRA_INDEX_URL
+        mcount "buildvar.PIP_EXTRA_INDEX_URL"
+    fi
 
-# Smart Requirements handling
+    set +e
-cp requirements.txt .heroku/python/requirements-declared.txt
-/app/.heroku/python/bin/pip freeze > .heroku/python/requirements-installed.txt
 
-[ ! "$FRESH_PYTHON" ] && bpwatch stop pip_install
+    # Set SLUGIFY_USES_TEXT_UNIDECODE, required for Airflow versions >=1.10
-[ "$FRESH_PYTHON" ] && bpwatch stop pip_install_first
+    if [[ -r "$ENV_DIR/SLUGIFY_USES_TEXT_UNIDECODE" ]]; then
+        SLUGIFY_USES_TEXT_UNIDECODE="$(cat "$ENV_DIR/SLUGIFY_USES_TEXT_UNIDECODE")"
+        export SLUGIFY_USES_TEXT_UNIDECODE
+        mcount "buildvar.SLUGIFY_USES_TEXT_UNIDECODE"
+    fi
 
-echo
+    set +e
+
+    # Measure that we're using pip.
+    mcount "tool.pip"
+
+    # Count expected build failures.
+    if grep -q '==0.0.0' requirements.txt; then
+        mcount "failure.none-version"
+    fi
+
+    if [ ! -f "$BUILD_DIR/.heroku/python/bin/pip" ]; then
+        exit 1
+    fi
+    /app/.heroku/python/bin/pip install -r "$BUILD_DIR/requirements.txt" --exists-action=w --src=/app/.heroku/src --disable-pip-version-check --no-cache-dir 2>&1 | tee "$WARNINGS_LOG" | cleanup | indent
+    PIP_STATUS="${PIPESTATUS[0]}"
+    set -e
+
+    show-warnings
+
+    if [[ ! $PIP_STATUS -eq 0 ]]; then
+        mcount "failure.pip-install"
+        exit 1
+    fi
+
+    # Smart Requirements handling
+    cp requirements.txt .heroku/python/requirements-declared.txt
+    /app/.heroku/python/bin/pip freeze --disable-pip-version-check > .heroku/python/requirements-installed.txt
+
+    echo
+
+    # Install test dependencies, for CI.
+    if [ "$INSTALL_TEST" ]; then
+        if [[ -f "$1/requirements-test.txt" ]]; then
+            puts-step "Installing test dependencies…"
+            /app/.heroku/python/bin/pip install -r "$1/requirements-test.txt" --exists-action=w --src=./.heroku/src --disable-pip-version-check --no-cache-dir 2>&1 | cleanup | indent
+        fi
+    fi
+fi

bin/steps/pip-uninstall

@@ -1,18 +1,28 @@
+#!/usr/bin/env bash
+
 set +e
 # Install dependencies with Pip.
-bpwatch start pip_uninstall
+# shellcheck source=bin/utils
-if [[ -f .heroku/python/requirements-declared.txt ]]; then
+source "$BIN_DIR/utils"
 
-  cp .heroku/python/requirements-declared.txt requirements-declared.txt
+if [ ! "$SKIP_PIP_INSTALL" ]; then
 
-  pip-diff --stale requirements-declared.txt requirements.txt > .heroku/python/requirements-stale.txt
+  if [[ -f .heroku/python/requirements-declared.txt ]]; then
 
-  rm -fr requirements-declared.txt
+    cp .heroku/python/requirements-declared.txt requirements-declared.txt
 
-  if [[ -s .heroku/python/requirements-stale.txt ]]; then
+
-    puts-step "Uninstalling stale dependencies"
+    if ! pip-diff --stale requirements-declared.txt requirements.txt --exclude setuptools pip wheel > .heroku/python/requirements-stale.txt; then
-    /app/.heroku/python/bin/pip uninstall -r .heroku/python/requirements-stale.txt -y --exists-action=w | cleanup | indent
+      mcount "failure.bad-requirements"
+    fi
+
+    rm -fr requirements-declared.txt
+
+    if [[ -s .heroku/python/requirements-stale.txt ]]; then
+      puts-step "Uninstalling stale dependencies"
+      /app/.heroku/python/bin/pip uninstall -r .heroku/python/requirements-stale.txt -y --exists-action=w --disable-pip-version-check | cleanup | indent
+    fi
   fi
+
 fi
-bpwatch stop pip_uninstall
+set -e
-set -e

bin/steps/pipenv

@@ -0,0 +1,86 @@
+#!/usr/bin/env bash
+
+# export CLINT_FORCE_COLOR=1
+# export PIPENV_FORCE_COLOR=1
+# shellcheck source=bin/utils
+source "$BIN_DIR/utils"
+set -e
+
+if [[ -f Pipfile.lock ]]; then
+    if [[ -f .heroku/python/Pipfile.lock.sha256 ]]; then
+        if [[ $(openssl dgst -sha256 Pipfile.lock) == $(cat .heroku/python/Pipfile.lock.sha256) ]]; then
+            # Measure that we're using Pipenv.
+            mcount "tool.pipenv"
+
+            # Don't skip installation of there are git deps.
+            if ! grep -q 'git' Pipfile.lock; then
+                echo "Skipping installation, as Pipfile.lock hasn't changed since last deploy." | indent
+
+                mcount "tool.pipenv"
+                export SKIP_PIPENV_INSTALL=1
+                export SKIP_PIP_INSTALL=1
+            fi
+        fi
+    fi
+fi
+
+
+if [ ! "$SKIP_PIPENV_INSTALL" ]; then
+    # Pipenv support (Generate requirements.txt with pipenv).
+    if [[ -f Pipfile ]]; then
+        # Measure that we're using Pipenv.
+        mcount "tool.pipenv"
+
+        # Skip pip install, later.
+        export SKIP_PIP_INSTALL=1
+
+        # Set Pip env vars
+        # This reads certain environment variables set on the Heroku app config
+        # and makes them accessible to the pip install process.
+        #
+        # PIP_EXTRA_INDEX_URL allows for an alternate pypi URL to be used.
+        if [[ -r "$ENV_DIR/PIP_EXTRA_INDEX_URL" ]]; then
+            PIP_EXTRA_INDEX_URL="$(cat "$ENV_DIR/PIP_EXTRA_INDEX_URL")"
+            export PIP_EXTRA_INDEX_URL
+            mcount "buildvar.PIP_EXTRA_INDEX_URL"
+        fi
+
+        # Set SLUGIFY_USES_TEXT_UNIDECODE, required for Airflow versions >=1.10
+        if [[ -r "$ENV_DIR/SLUGIFY_USES_TEXT_UNIDECODE" ]]; then
+            SLUGIFY_USES_TEXT_UNIDECODE="$(cat "$ENV_DIR/SLUGIFY_USES_TEXT_UNIDECODE")"
+            export SLUGIFY_USES_TEXT_UNIDECODE
+            mcount "buildvar.SLUGIFY_USES_TEXT_UNIDECODE"
+        fi
+
+        export PIPENV_VERSION="2018.5.18"
+
+        # Install pipenv.
+        # Due to weird old pip behavior and pipenv behavior, pipenv upgrades pip
+        # to latest if only --upgrade is specified. Specify upgrade strategy to
+        # avoid this eager behavior.
+        /app/.heroku/python/bin/pip install pipenv==$PIPENV_VERSION --upgrade --upgrade-strategy only-if-needed &> /dev/null
+
+        # Install the test dependencies, for CI.
+        if [ "$INSTALL_TEST" ]; then
+            puts-step "Installing test dependencies…"
+            /app/.heroku/python/bin/pipenv install --dev --system --deploy 2>&1 | cleanup | indent
+
+        # Install the dependencies.
+        elif [[ ! -f Pipfile.lock ]]; then
+            puts-step "Installing dependencies with Pipenv $PIPENV_VERSION…"
+            /app/.heroku/python/bin/pipenv install --system --skip-lock 2>&1 | indent
+
+        else
+            pipenv-to-pip Pipfile.lock > requirements.txt
+            "$BIN_DIR/steps/pip-uninstall"
+            cp requirements.txt .heroku/python/requirements-declared.txt
+            openssl dgst -sha256 Pipfile.lock > .heroku/python/Pipfile.lock.sha256
+
+            puts-step "Installing dependencies with Pipenv $PIPENV_VERSION…"
+            /app/.heroku/python/bin/pipenv install --system --deploy 2>&1 | indent
+        fi
+    fi
+else
+    export SKIP_PIP_INSTALL=1
+    pipenv-to-pip Pipfile.lock > requirements.txt
+fi

bin/steps/pipenv-python-version

@@ -0,0 +1,35 @@
+#!/usr/bin/env bash
+
+# Detect Python-version with Pipenv.
+
+if [[ -f $BUILD_DIR/Pipfile ]]; then
+
+    if [[ ! -f $BUILD_DIR/runtime.txt ]]; then
+        if [[ ! -f $BUILD_DIR/Pipfile.lock ]]; then
+            puts-warn "No 'Pipfile.lock' found! We recommend you commit this into your repository."
+        fi
+        if [[ -f $BUILD_DIR/Pipfile.lock ]]; then
+            set +e
+            PYTHON=$(jq -r '._meta.requires.python_full_version' "$BUILD_DIR/Pipfile.lock")
+            if [[ "$PYTHON" != "null" ]]; then
+                echo "python-$PYTHON" > "$BUILD_DIR/runtime.txt"
+            fi
+            set -e
+
+            if [[ "$PYTHON" == "null" ]]; then
+                PYTHON=$(jq -r '._meta.requires.python_version' "$BUILD_DIR/Pipfile.lock")
+                if [ "$PYTHON" = 2.7 ]; then
+                    echo "$LATEST_27" > "$BUILD_DIR/runtime.txt"
+                fi
+                if [ "$PYTHON" = 3.6 ]; then
+                    echo "$LATEST_36" > "$BUILD_DIR/runtime.txt"
+                fi
+                if [ "$PYTHON" = 3.7 ]; then
+                    echo "$LATEST_37" > "$BUILD_DIR/runtime.txt"
+                fi
+            fi
+
+
+        fi
+    fi
+fi

bin/steps/pylibmc

@@ -4,33 +4,34 @@
 # [**Python Buildpack**](https://github.com/heroku/heroku-buildpack-python)
 # compiler.
 #
-# A [buildpack](http://devcenter.heroku.com/articles/buildpacks) is an
+# A [buildpack](https://devcenter.heroku.com/articles/buildpacks) is an
 # adapter between a Python application and Heroku's runtime.
 #
 # This script is invoked by [`bin/compile`](/).
 
+if [[ "$STACK" != "cedar-14" ]]; then
+    # libmemcached is pre-installed in the stack image so there is no need to vendor it.
+    return 0
+fi
+
 # The location of the pre-compiled libmemcached binary.
-VENDORED_MEMCACHED="http://lang-python.s3.amazonaws.com/$STACK/libraries/vendor/libmemcache.tar.gz"
+VENDORED_MEMCACHED="${VENDOR_URL}/libraries/vendor/libmemcache.tar.gz"
 
 # Syntax sugar.
-source $BIN_DIR/utils
+# shellcheck source=bin/utils
-
+source "$BIN_DIR/utils"
-
-bpwatch start pylibmc_install
 
 # If pylibmc exists within requirements, use vendored libmemcached.
 if (pip-grep -s requirements.txt pylibmc &> /dev/null) then
 
-  if [ -d ".heroku/vendor/lib/sasl2" ]; then
+  if [ ! -d ".heroku/vendor/lib/sasl2" ]; then
-    export LIBMEMCACHED=$(pwd)/vendor
-  else
     echo "-----> Noticed pylibmc. Bootstrapping libmemcached."
     mkdir -p .heroku/vendor
     # Download and extract libmemcached into target vendor directory.
-    curl $VENDORED_MEMCACHED -s | tar zxv -C .heroku/vendor &> /dev/null
+    curl "$VENDORED_MEMCACHED" -s | tar zxv -C .heroku/vendor &> /dev/null
-
+    mcount "steps.vendor.pylibmc"
-    export LIBMEMCACHED=$(pwd)/vendor
   fi
-fi
 
-bpwatch stop pylibmc_install
+  LIBMEMCACHED=$(pwd)/vendor
+  export LIBMEMCACHED
+fi

bin/steps/python

@@ -1,78 +1,153 @@
+#!/usr/bin/env bash
+
 set +e
+runtime-fixer runtime.txt
 PYTHON_VERSION=$(cat runtime.txt)
 
-# Install Python.
+# The location of the pre-compiled python binary.
+VENDORED_PYTHON="${VENDOR_URL}/runtimes/$PYTHON_VERSION.tar.gz"
+
+SECURITY_UPDATE="Python has released a security update! Please consider upgrading to"
+
+ONLY_SUPPORTED_2_VERSION="Only the latest version of Python 2 is supported on the platform. Please consider upgrading to"
+
+PYTHON_2_EOL_UPDATE="Python 2 has reached it's community EOL. Upgrade your Python runtime to maintain a secure application as soon as possible."
+
+# check if runtime exists
+if curl --output /dev/null --silent --head --fail "$VENDORED_PYTHON"; then
+  if [[ "$PYTHON_VERSION" == $PY38* ]]; then
+    # do things to alert the user of security release available
+    if [ "$PYTHON_VERSION" != "$LATEST_38" ]; then
+      puts-warn "$SECURITY_UPDATE" "$LATEST_38"
+      echo "       Learn More: https://devcenter.heroku.com/articles/python-runtimes"
+    fi
+  fi
+  if [[ "$PYTHON_VERSION" == $PY37* ]]; then
+    # do things to alert the user of security release available
+    if [ "$PYTHON_VERSION" != "$LATEST_37" ]; then
+      puts-warn "$SECURITY_UPDATE" "$LATEST_37"
+      echo "       Learn More: https://devcenter.heroku.com/articles/python-runtimes"
+    fi
+  fi
+  if [[ "$PYTHON_VERSION" == $PY36* ]]; then
+    # security update note
+    if [ "$PYTHON_VERSION" != "$LATEST_36" ]; then
+      puts-warn "$SECURITY_UPDATE" "$LATEST_36"
+      echo "       Learn More: https://devcenter.heroku.com/articles/python-runtimes"
+    fi
+  fi
+  if [[ "$PYTHON_VERSION" == $PY35* ]]; then
+    # security update note
+    if [ "$PYTHON_VERSION" != "$LATEST_35" ]; then
+      puts-warn "$SECURITY_UPDATE" "$LATEST_35"
+      echo "       Learn More: https://devcenter.heroku.com/articles/python-runtimes"
+    fi
+  fi
+  if [[ "$PYTHON_VERSION" == $PY34* ]]; then
+    # security update note
+    if [ "$PYTHON_VERSION" != "$LATEST_34" ]; then
+      puts-warn "$SECURITY_UPDATE" "$LATEST_34"
+      echo "       Learn More: https://devcenter.heroku.com/articles/python-runtimes"
+    fi
+  fi
+  if [[ "$PYTHON_VERSION" == $PY27* ]]; then
+    # security update note
+    if [[ "$(date "+%Y")" -gt "2019" ]]; then
+      puts-warn "$PYTHON_2_EOL_UPDATE"
+      echo "       Learn More: https://devcenter.heroku.com/articles/python-2-7-eol-faq"
+    fi
+    if [ "$PYTHON_VERSION" != "$LATEST_27" ]; then
+      puts-warn "$ONLY_SUPPORTED_2_VERSION" "$LATEST_27"
+      echo "       Learn More: https://devcenter.heroku.com/articles/python-runtimes"
+    fi
+  fi
+  if [[ "$PYTHON_VERSION" == $PYPY27* ]]; then
+    # security update note
+    if [ "$PYTHON_VERSION" != "$PYPY_27" ]; then
+      puts-warn "Could not find that Pypy version. Did you mean" "${PYPY_27}?"
+      echo "       Learn More: https://devcenter.heroku.com/articles/python-runtimes"
+    fi
+  fi
+  if [[ "$PYTHON_VERSION" == $PYPY36* ]]; then
+    # security update note
+    if [ "$PYTHON_VERSION" != "$PYPY_36" ]; then
+      puts-warn "Could not find that Pypy version. Did you mean" "${PYPY_36}?"
+      echo "       Learn More: https://devcenter.heroku.com/articles/python-runtimes"
+    fi
+  fi
+else
+  puts-warn "Requested runtime ($PYTHON_VERSION) is not available for this stack ($STACK)."
+  puts-warn "Aborting.  More info: https://devcenter.heroku.com/articles/python-support"
+  exit 1
+fi
+
+if [[ "$STACK" != "$CACHED_PYTHON_STACK" ]]; then
+    puts-step "Stack has changed from $CACHED_PYTHON_STACK to $STACK, clearing cache"
+    rm -fr .heroku/python-stack .heroku/python-version .heroku/python .heroku/vendor .heroku/python .heroku/python-sqlite3-version
+fi
+
+# need to clear the cache for first time installing SQLite3,
+# since the version is changing and could lead to runtime errors
+# with compiled extensions.
+if [ -d .heroku/python ] && [ ! -f .heroku/python-sqlite3-version ] && python_sqlite3_check "$PYTHON_VERSION"; then
+  puts-step "Need to update SQLite3, clearing cache"
+  rm -fr .heroku/python-stack .heroku/python-version .heroku/python .heroku/vendor
+fi
+
 if [ -f .heroku/python-version ]; then
-  if [ ! $(cat .heroku/python-version) = $PYTHON_VERSION ]; then
+  if [ ! "$(cat .heroku/python-version)" = "$PYTHON_VERSION" ]; then
-    bpwatch start uninstall_python
+      puts-step "Found $(cat .heroku/python-version), removing"
-      puts-step "Found runtime $(cat .heroku/python-version), removing"
       rm -fr .heroku/python
-    bpwatch stop uninstall_python
   else
     SKIP_INSTALL=1
   fi
 fi
 
-if [ ! $STACK = $CACHED_PYTHON_STACK ]; then
-  bpwatch start uninstall_python
-    puts-step "Stack changed, re-installing runtime"
-    rm -fr .heroku/python .heroku/python-stack .heroku/vendor
-    unset SKIP_INSTALL
-  bpwatch stop uninstall_python
-fi
-
 
 if [ ! "$SKIP_INSTALL" ]; then
-  bpwatch start install_python
+    puts-step "Installing $PYTHON_VERSION"
-    puts-step "Installing runtime ($PYTHON_VERSION)"
 
     # Prepare destination directory.
     mkdir -p .heroku/python
 
-    curl http://lang-python.s3.amazonaws.com/$STACK/runtimes/$PYTHON_VERSION.tar.gz -s | tar zxv -C .heroku/python &> /dev/null
+    mcount "version.python.$PYTHON_VERSION"
-    if [[ $? != 0 ]] ; then
+
+    if ! curl "${VENDORED_PYTHON}" -s | tar zxv -C .heroku/python &> /dev/null; then
       puts-warn "Requested runtime ($PYTHON_VERSION) is not available for this stack ($STACK)."
       puts-warn "Aborting.  More info: https://devcenter.heroku.com/articles/python-support"
       exit 1
     fi
 
-  bpwatch stop install_python
-
   # Record for future reference.
-  echo $PYTHON_VERSION > .heroku/python-version
+  echo "$PYTHON_VERSION" > .heroku/python-version
-  echo $STACK > .heroku/python-stack
+  echo "$STACK" > .heroku/python-stack
   FRESH_PYTHON=true
 
   hash -r
 fi
 
+# Heroku uses the get-pip utility maintained by the Python community to vendor Pip.
+# https://github.com/pypa/get-pip
+GETPIP_URL="https://lang-python.s3.amazonaws.com/etc/get-pip.py"
+GETPIP_PY="${TMPDIR:-/tmp}/get-pip.py"
+
+if ! curl -s "${GETPIP_URL}" -o "$GETPIP_PY" &> /dev/null; then
+    mcount "failure.python.get-pip"
+    echo "Failed to pull down get-pip"
+    exit 1
+fi
+
 # If Pip isn't up to date:
-if [ "$FRESH_PYTHON" ] || [[ ! $(pip --version) == *$PIP_VERSION* ]]; then
+if [ "$FRESH_PYTHON" ] || [[ ! $(pip --version) == *$PIP_UPDATE* ]]; then
-  WORKING_DIR=$(pwd)
 
-  bpwatch start prepare_environment
+  puts-step "Installing pip"
 
-  TMPTARDIR=$(mktemp -d)
+  # Remove old installations.
-  trap "rm -rf $TMPTARDIR" RETURN
+  rm -fr /app/.heroku/python/lib/python*/site-packages/pip-*
+  rm -fr /app/.heroku/python/lib/python*/site-packages/setuptools-*
 
-  bpwatch start install_setuptools
+  /app/.heroku/python/bin/python "$GETPIP_PY" pip=="$PIP_UPDATE" &> /dev/null
-    # Prepare it for the real world
+  /app/.heroku/python/bin/pip install "$ROOT_DIR/vendor/setuptools-39.0.1-py2.py3-none-any.whl" &> /dev/null
-    # puts-step "Installing Setuptools ($SETUPTOOLS_VERSION)"
-    tar zxf $ROOT_DIR/vendor/setuptools-$SETUPTOOLS_VERSION.tar.gz -C $TMPTARDIR
-    cd $TMPTARDIR/setuptools-$SETUPTOOLS_VERSION/
-    python setup.py install &> /dev/null
-    cd $WORKING_DIR
-  bpwatch stop install_setuptoools
-
-  bpwatch start install_pip
-    # puts-step "Installing Pip ($PIP_VERSION)"
-    tar zxf $ROOT_DIR/vendor/pip-$PIP_VERSION.tar.gz -C $TMPTARDIR
-    cd $TMPTARDIR/pip-$PIP_VERSION/
-    python setup.py install &> /dev/null
-    cd $WORKING_DIR
-
-  bpwatch stop install_pip
-  bpwatch stop prepare_environment
 fi
 
 set -e

bin/steps/setuptools

@@ -1,11 +0,0 @@
-#!/usr/bin/env bash
-
-# Syntax sugar.
-source $BIN_DIR/utils
-
-if (pip-grep -s requirements.txt setuptools distribute &> /dev/null) then
-
-  puts-warn 'The package setuptools/distribute is listed in requirements.txt.'
-  puts-warn 'Please remove to ensure expected behavior. '
-
-fi

bin/steps/sqlite3

@@ -0,0 +1,78 @@
+#!/usr/bin/env bash
+
+# shellcheck source=bin/utils
+source "$BIN_DIR/utils"
+
+sqlite3_install() {
+  HEROKU_PYTHON_DIR="$1"
+  HEADERS_ONLY="$3"
+
+  mkdir -p "$HEROKU_PYTHON_DIR"
+
+  APT_CACHE_DIR="$HEROKU_PYTHON_DIR/apt/cache"
+  APT_STATE_DIR="$HEROKU_PYTHON_DIR/apt/state"
+
+  mkdir -p "$APT_CACHE_DIR/archives/partial"
+  mkdir -p "$APT_STATE_DIR/lists/partial"
+
+  APT_OPTIONS="-o debug::nolocking=true"
+  APT_OPTIONS="$APT_OPTIONS -o dir::cache=$APT_CACHE_DIR"
+  APT_OPTIONS="$APT_OPTIONS -o dir::state=$APT_STATE_DIR"
+  APT_OPTIONS="$APT_OPTIONS -o dir::etc::sourcelist=/etc/apt/sources.list"
+
+  apt-get $APT_OPTIONS update > /dev/null 2>&1
+  if [ -z "$HEADERS_ONLY" ]; then
+    apt-get $APT_OPTIONS -y -d --reinstall install libsqlite3-dev sqlite3 > /dev/null 2>&1
+  else
+    apt-get $APT_OPTIONS -y -d --reinstall install libsqlite3-dev
+  fi
+
+  find "$APT_CACHE_DIR/archives/" -name "*.deb" -exec dpkg -x {} "$HEROKU_PYTHON_DIR/sqlite3/" \;
+
+  mkdir -p "$HEROKU_PYTHON_DIR/include"
+  mkdir -p "$HEROKU_PYTHON_DIR/lib"
+
+  # remove old sqlite3 libraries/binaries
+  find "$HEROKU_PYTHON_DIR/include/" -name "sqlite3*.h" -exec rm -f {} \;
+  find "$HEROKU_PYTHON_DIR/lib/" -name "libsqlite3.*" -exec rm -f {} \;
+  rm -f "$HEROKU_PYTHON_DIR/lib/pkgconfig/sqlite3.pc"
+  rm -f "$HEROKU_PYTHON_DIR/bin/sqlite3"
+
+  # copy over sqlite3 headers & bins and setup linking against the stack image library
+  mv "$HEROKU_PYTHON_DIR/sqlite3/usr/include/"* "$HEROKU_PYTHON_DIR/include/"
+  mv "$HEROKU_PYTHON_DIR/sqlite3/usr/lib/x86_64-linux-gnu"/libsqlite3.*a "$HEROKU_PYTHON_DIR/lib/"
+  mkdir -p "$HEROKU_PYTHON_DIR/lib/pkgconfig"
+  # set the right prefix/lib directories
+  sed -e 's/prefix=\/usr/prefix=\/app\/.heroku\/python/' -e 's/\/x86_64-linux-gnu//' "$HEROKU_PYTHON_DIR/sqlite3/usr/lib/x86_64-linux-gnu/pkgconfig/sqlite3.pc" > "$HEROKU_PYTHON_DIR/lib/pkgconfig/sqlite3.pc"
+  # need to point the libsqlite3.so to the stack image library for /usr/bin/ld -lsqlite3
+  SQLITE3_LIBFILE="/usr/lib/x86_64-linux-gnu/$(readlink -n "$HEROKU_PYTHON_DIR/sqlite3/usr/lib/x86_64-linux-gnu/libsqlite3.so")"
+  ln -s "$SQLITE3_LIBFILE" "$HEROKU_PYTHON_DIR/lib/libsqlite3.so"
+  if [ -z "$HEADERS_ONLY" ]; then
+    mv "$HEROKU_PYTHON_DIR/sqlite3/usr/bin"/* "$HEROKU_PYTHON_DIR/bin/"
+  fi
+
+  # cleanup
+  rm -rf "$HEROKU_PYTHON_DIR/sqlite3/"
+  rm -rf "$HEROKU_PYTHON_DIR/apt/"
+}
+
+buildpack_sqlite3_install() {
+  HEROKU_PYTHON_DIR="$BUILD_DIR/.heroku/python"
+
+  SQLITE3_VERSION_FILE="$BUILD_DIR/.heroku/python-sqlite3-version"
+  if [ -f "$SQLITE3_VERSION_FILE" ]; then
+    INSTALLED_SQLITE3_VERSION=$(cat "$SQLITE3_VERSION_FILE")
+  fi
+
+  puts-step "Installing SQLite3"
+
+  if sqlite3_install "$BUILD_DIR/.heroku/python" ; then
+    echo "Sqlite3 successfully installed."
+    mcount "success.python.sqlite3"
+  else
+    echo "Sqlite3 failed to install."
+    mcount "failure.python.sqlite3"
+  fi
+
+  mkdir -p "$CACHE_DIR/.heroku/"
+}

bin/test

@@ -1,106 +0,0 @@
-#!/usr/bin/env bash
-
-#
-# Create a Heroku app with the following buildpack:
-# https://github.com/ddollar/buildpack-test
-#
-# Push this Python buildpack to that Heroku app to
-# run the tests.
-#
-
-testDetectWithReqs() {
-  detect "simple-requirements"
-  assertCapturedEquals "Python"
-  assertCapturedSuccess
-}
-
-testDetectWithEmptyReqs() {
-  detect "empty-requirements"
-  assertCapturedEquals "Python"
-  assertCapturedSuccess
-}
-
-testDetectDjango16() {
-  detect "django-1.6-skeleton"
-  assertCapturedEquals "Python"
-  assertCapturedSuccess
-}
-
-testDetectDjango15() {
-  detect "django-1.5-skeleton"
-  assertCapturedEquals "Python"
-  assertCapturedSuccess
-}
-
-testDetectDjango14() {
-  detect "django-1.4-skeleton"
-  assertCapturedEquals "Python"
-  assertCapturedSuccess
-}
-
-testDetectDjango13() {
-  detect "django-1.3-skeleton"
-  assertCapturedEquals "Python"
-  assertCapturedSuccess
-}
-
-testDetectNotDjangoWithSettings() {
-  detect "not-django"
-  assertCapturedEquals "Python"
-  assertCapturedSuccess
-}
-
-testDetectWithSetupPy() {
-  detect "distutils"
-  assertCapturedEquals "Python"
-  assertCapturedSuccess
-}
-
-testDetectWithSetupRequires() {
-  detect "no-requirements"
-  assertCapturedEquals "Python"
-  assertCapturedSuccess
-}
-
-testDetectNotPython() {
-  detect "not-python"
-  assertNotCaptured "Python"
-  assertEquals "1" "${RETURN}"
-}
-
-testDetectSimpleRuntimePypy2() {
-  detect "simple-runtime-pypy2"
-  assertCapturedEquals "Python"
-  assertCapturedSuccess
-}
-
-testDetectSimpleRuntimePython2() {
-  detect "simple-runtime-python2"
-  assertCapturedEquals "Python"
-  assertCapturedSuccess
-}
-
-testDetectSimpleRuntimePython3() {
-  detect "simple-runtime"  # should probably be renamed simple-runtime-python3
-  assertCapturedEquals "Python"
-  assertCapturedSuccess
-}
-
-## utils ########################################
-
-pushd $(dirname 0) >/dev/null
-BASE=$(pwd)
-popd >/dev/null
-
-source ${BASE}/vendor/test-utils
-
-detect() {
-  capture ${BASE}/bin/detect ${BASE}/test/$1
-}
-
-compile() {
-  capture ${BASE}/bin/compile ${BASE}/test/$1
-}
-
-source ${BASE}/vendor/shunit2
-

bin/test-compile

@@ -0,0 +1,13 @@
+#!/usr/bin/env bash
+
+# Syntax sugar.
+BIN_DIR=$(cd "$(dirname "$0")" || return; pwd) # absolute path
+
+# shellcheck source=bin/utils
+source "$BIN_DIR/utils"
+
+# Locale support for Pipenv.
+export LC_ALL=C.UTF-8
+export LANG=C.UTF-8
+
+DISABLE_COLLECTSTATIC=1 INSTALL_TEST=1 "$(dirname "${0:-}")/compile" "$1" "$2" "$3"

bin/utils

@@ -1,6 +1,15 @@
+#!/usr/bin/env bash
 shopt -s extglob
+shopt -s nullglob
 
-if [ $(uname) == Darwin ]; then
+# The standard library.
+if [[ ! -f  /tmp/stdlib.sh ]]; then
+  curl --retry 3 -s https://lang-common.s3.amazonaws.com/buildpack-stdlib/v8/stdlib.sh > /tmp/stdlib.sh
+fi
+# shellcheck source=/dev/null
+source /tmp/stdlib.sh
+
+if [ "$(uname)" == Darwin ]; then
     sed() { command sed -l "$@"; }
 else
     sed() { command sed -u "$@"; }
@@ -11,34 +20,20 @@ indent() {
   sed "s/^/       /"
 }
 
+
 # Clean up pip output
 cleanup() {
-  sed -e 's/\.\.\.\+/.../g' | sed -e '/already satisfied/Id' | sed -e '/Overwriting/Id' | sed -e '/python executable/Id' | sed -e '/no previously-included files/Id'
+  sed -e 's/\.\.\.\+/.../g' | sed -e '/already satisfied/Id' | sed -e '/No files were found to uninstall/Id' | sed -e '/Overwriting/Id' | sed -e '/python executable/Id' | sed -e '/no previously-included files/Id'
 }
 
 # Buildpack Steps.
 puts-step() {
-  echo "-----> $@"
+  echo "-----> $*"
 }
 
 # Buildpack Warnings.
 puts-warn() {
-  echo " !     $@"
+  echo " !     $*"
-}
-
-# Usage: $ set-env key value
-set-env() {
-  echo "export $1=$2" >> $PROFILE_PATH
-}
-
-# Usage: $ set-default-env key value
-set-default-env() {
-  echo "export $1=\${$1:-$2}" >> $PROFILE_PATH
-}
-
-# Usage: $ set-default-env key value
-un-set-env() {
-  echo "unset $1" >> $PROFILE_PATH
 }
 
 # Does some serious copying.
@@ -57,37 +52,46 @@ deep-cp() {
   )
 }
 
-# Does some serious moving.
+
-deep-mv() {
+# Measure the size of the Python installation.
-  deep-cp "$1" "$2"
+measure-size() {
-  deep-rm "$1"
+  echo "$(du -s .heroku/python 2>/dev/null || echo 0) | awk '{print $1}')"
 }
 
-# Does some serious deleting.
+# Python version operator >
-deep-rm() {
+version_gt() {
-  # subshell to avoid surprising caller with shopts.
+  test "$(printf '%s\n' "$@" | sort -V | head -n 1)" != "$1";
-  (
-    shopt -s dotglob
-    rm -rf "$1"/!(tmp|.|..)
-  )
 }
 
+# Python verison operator >=
+version_gte() {
+  if [ "$1" == "$2" ]; then
+    return 0
+  fi
 
-sub-env() {
+  version_gt "$1" "$2"
-
+}
-  WHITELIST=${2:-''}
+
-  BLACKLIST=${3:-'^(GIT_DIR|PYTHONHOME|LD_LIBRARY_PATH|LIBRARY_PATH|PATH)$'}
+# Check if Python 2
-
+python2_check() {
-  (
+  VERSION="$1"
-    if [ -d "$ENV_DIR" ]; then
+
-      for e in $(ls $ENV_DIR); do
+  version_gte "$VERSION" "python-2.7.0" && version_gt "python-3.0.0" "$VERSION"
-        echo "$e" | grep -E "$WHITELIST" | grep -qvE "$BLACKLIST" &&
+}
-        export "$e=$(cat $ENV_DIR/$e)"
+
-        :
+# Check if Python 3
-      done
+python3_check() {
-    fi
+  VERSION="$1"
-
+
-    $1
+  version_gte "$VERSION" "python-3.0.0" && version_gt "python-4.0.0" "$VERSION"
-
+}
-  )
+
+# Check if Python version needs to install SQLite3
+python_sqlite3_check() {
+  VERSION="$1"
+  MIN_PYTHON_3="python-3.5.6"
+  MIN_PYTHON_2="python-2.7.15"
+
+  ( python2_check "$VERSION" && version_gte "$VERSION" "$MIN_PYTHON_2" ) \
+    || ( python3_check "$VERSION" && version_gte "$VERSION" "$MIN_PYTHON_3" )
 }

bin/warnings

@@ -0,0 +1,66 @@
+#!/usr/bin/env bash
+shopt -s extglob
+
+old-platform() {
+  if grep -qi 'InsecurePlatformWarning' "$WARNINGS_LOG"; then
+    echo
+    puts-warn "Hello! It looks like your application is using an outdated version of Python."
+    puts-warn "This caused the security warning you saw above during the 'pip install' step."
+    puts-warn "We recommend '$RECOMMENDED_PYTHON_VERSION', which you can specify in a 'runtime.txt' file."
+    puts-warn "  -- Much Love, Heroku."
+    mcount 'warnings.python.old'
+  fi
+}
+
+pylibmc-missing() {
+  if grep -qi 'fatal error: libmemcached/memcached.h: No such file or directory' "$WARNINGS_LOG"; then
+    echo
+    puts-warn "Hello! There was a problem with your build related to libmemcache."
+    puts-warn "The Python library 'pylibmc' must be explicitly specified in 'requirements.txt' in order to build correctly."
+    puts-warn "Once you do that, everything should work as expected.   -- Much Love, Heroku."
+    mcount 'warnings.libmemcache'
+  fi
+}
+
+scipy-included() {
+  if grep -qi 'running setup.py install for scipy' "$WARNINGS_LOG"; then
+    echo
+    puts-warn "Hello! It looks like you're trying to use scipy on Heroku."
+    puts-warn "Unfortunately, at this time, we do not directly support this library."
+    puts-warn "There is, however, a buildpack available that makes it possible to use it on Heroku."
+    puts-warn "You can learn more here:  https://devcenter.heroku.com/articles/python-c-deps"
+    puts-warn "Sorry for the inconvenience.   -- Much Love, Heroku."
+    mcount 'warnings.scipy'
+  fi
+}
+
+distribute-included() {
+  if grep -qi 'Running setup.py install for distribute' "$WARNINGS_LOG"; then
+    echo
+    puts-warn "Hello! Your requirements.txt file contains the distribute package."
+    puts-warn "This library is automatically installed by Heroku and shouldn't be in"
+    puts-warn "Your requirements.txt file. This can cause unexpected behavior."
+    puts-warn "  -- Much Love, Heroku."
+    mcount 'warnings.distribute'
+  fi
+}
+
+six-included() {
+  if grep -qi 'Running setup.py install for six' "$WARNINGS_LOG"; then
+    echo
+    puts-warn "Hello! Your requirements.txt file contains the six package."
+    puts-warn "This library is automatically installed by Heroku and shouldn't be in"
+    puts-warn "Your requirements.txt file. This can cause unexpected behavior."
+    puts-warn "  -- Much Love, Heroku."
+    mcount 'warnings.six'
+  fi
+}
+
+show-warnings() {
+  old-platform
+  pylibmc-missing
+  scipy-included
+  distribute-included
+  six-included
+}
+

buildpack.toml

@@ -0,0 +1,13 @@
+[buildpack]
+name = "Python"
+
+  [publish.Ignore]
+  files = [
+    "test/",
+    ".gitignore",
+    ".dockerignore",
+    ".github/",
+    "Dockerfile",
+    "Pipfile",
+    "Pipfile.lock"
+  ]

builds/README.md

@@ -1,31 +1,57 @@
 # Python Buildpack Binaries
 
+## Building the Docker Images
 
-To get started with it, create an app on Heroku inside a clone of this repository, and set your S3 config vars:
+**After every change to your formulae, perform the following** from the root of the Git repository (not from `builds/`) to rebuild the images for each stack:
 
-    $ heroku create --buildpack https://github.com/heroku/heroku-buildpack-python#not-heroku
+    $ docker build --pull --tag heroku-python-build-cedar-14 --file $(pwd)/builds/cedar-14.Dockerfile .
-    $ heroku config:set WORKSPACE_DIR=builds
+    $ docker build --pull --tag heroku-python-build-heroku-16 --file $(pwd)/builds/heroku-16.Dockerfile .
-    $ heroku config:set AWS_ACCESS_KEY_ID=<your_aws_key>
+    $ docker build --pull --tag heroku-python-build-heroku-18 --file $(pwd)/builds/heroku-18.Dockerfile .
-    $ heroku config:set AWS_SECRET_ACCESS_KEY=<your_aws_secret>
-    $ heroku config:set S3_BUCKET=<your_s3_bucket_name>
 
+## Using the Image
 
-Then, shell into an instance and run a build by giving the name of the formula inside `builds`:
+You can e.g. `bash` into each of the images you built using their tag:
 
-    $ heroku run bash
+    docker run --rm -ti heroku-python-build-cedar-14 bash
-    Running `bash` attached to terminal... up, run.6880
+    docker run --rm -ti heroku-python-build-heroku-16 bash
-    ~ $ bob build runtimes/python-2.7.6
+    docker run --rm -ti heroku-python-build-heroku-18 bash
 
-    Fetching dependencies... found 2:
+You then have a shell where you can run `bob build`, `bob deploy`, and so forth. You can of course also invoke these programs directly with `docker run`:
-      - libraries/sqlite
 
-    Building formula runtimes/python-2.7.6:
+    docker run --rm -ti heroku-python-build-heroku-18 bob build runtimes/python-2.7.15
-        === Building Python 2.7.6
-        Fetching Python v2.7.6 source...
-        Compiling...
 
-If this works, run `bob deploy` instead of `bob build` to have the result uploaded to S3 for you.
+In order to `bob deploy`, AWS credentials must be set up, as well as name and prefix of your custom S3 bucket (unless you're deploying to the Heroku production buckets that are pre-defined in each `Dockerfile`); see next section for details.
 
-To speed things up drastically, it'll usually be a good idea to `heroku run bash --size PX` instead.
+## Configuration
 
-Enjoy :)
+File `dockerenv.default` contains a list of required env vars; most of these have default values defined in `Dockerfile`. You can copy this file to a location outside the buildpack and modify it with the values you desire and pass its location with `--env-file`, or pass the env vars to `docker run` using `--env`.
+
+Out of the box, each `Dockerfile` has the correct values predefined for `S3_BUCKET`, `S3_PREFIX`, and `S3_REGION`. If you're building your own packages, you'll likely want to change `S3_BUCKET` and `S3_PREFIX` to match your info. Instead of setting `AWS_ACCESS_KEY_ID` and `AWS_SECRET_ACCESS_KEY` into that file, you may also pass them to `docker run` through the environment, or explicitly using `--env`, in order to prevent accidental commits of credentials.
+
+### Passing AWS credentials to the container
+
+If you want to deploy packages and thus need to pass `AWS_ACCESS_KEY_ID` and `AWS_SECRET_ACCESS_KEY`, you can either pass them explicitly, through your environment, or through an env file.
+
+#### Passing credentials explicitly
+
+    docker run --rm -ti -e AWS_ACCESS_KEY_ID=... -e AWS_SECRET_ACCESS_KEY=... heroku-python-build-heroku-18 bash
+
+#### Passing credentials through  the environment
+
+The two environment variables `AWS_ACCESS_KEY_ID`and `AWS_SECRET_ACCESS_KEY` are defined in `builds/dockerenv.default`, without values. This will cause Docker to "forward" values for these variables from the current environment, so you can pass them in:
+
+    AWS_ACCESS_KEY_ID=... AWS_SECRET_ACCESS_KEY=... docker run --rm -ti --env-file=builds/dockerenv.default heroku-python-build-heroku-18 bash
+
+or
+
+    export AWS_ACCESS_KEY_ID=...
+    export AWS_SECRET_ACCESS_KEY=...
+    docker run --rm -ti --env-file=builds/dockerenv.default heroku-python-build-heroku-18 bash
+
+#### Passing credentials through a separate env file
+
+This method is the easiest for users who want to build packages in their own S3 bucket, as they will have to adjust the `S3_BUCKET` and `S3_PREFIX` environment variable values anyway from their default values.
+
+For this method, it is important to keep the credentials file in a location outside the buildpack, so that your credentials aren't accidentally committed. Copy `builds/dockerenv.default` **to a safe location outside the buildpack directory**, and insert your values for `AWS_ACCESS_KEY_ID`and `AWS_SECRET_ACCESS_KEY`.
+
+    docker run --rm -ti --env-file=../SOMEPATHOUTSIDE/s3.env heroku-python-build-heroku-18 bash

builds/cedar-14.Dockerfile

@@ -0,0 +1,15 @@
+FROM heroku/cedar:14
+
+WORKDIR /app
+ENV WORKSPACE_DIR="/app/builds" \
+    S3_BUCKET="lang-python" \
+    S3_PREFIX="cedar-14/" \
+    DEBIAN_FRONTEND=noninteractive \
+    STACK="cedar-14"
+
+RUN apt-get update && apt-get install -y python-pip libsqlite3-dev realpath && rm -rf /var/lib/apt/lists/*
+
+COPY requirements.txt /app/
+RUN pip install -r /app/requirements.txt
+
+COPY . /app

builds/dockerenv.default

@@ -0,0 +1,5 @@
+AWS_ACCESS_KEY_ID
+AWS_SECRET_ACCESS_KEY
+S3_BUCKET
+S3_PREFIX
+S3_REGION

builds/heroku-16.Dockerfile

@@ -0,0 +1,15 @@
+FROM heroku/heroku:16-build
+
+WORKDIR /app
+ENV WORKSPACE_DIR="/app/builds" \
+    S3_BUCKET="lang-python" \
+    S3_PREFIX="heroku-16/" \
+    DEBIAN_FRONTEND=noninteractive \
+    STACK="heroku-16"
+
+RUN apt-get update && apt-get install -y python-pip libsqlite3-dev && rm -rf /var/lib/apt/lists/*
+
+COPY requirements.txt /app/
+RUN pip install --disable-pip-version-check --no-cache-dir -r /app/requirements.txt
+
+COPY . /app

builds/heroku-18.Dockerfile

@@ -0,0 +1,15 @@
+FROM heroku/heroku:18-build.v16
+
+WORKDIR /app
+ENV WORKSPACE_DIR="/app/builds" \
+    S3_BUCKET="lang-python" \
+    S3_PREFIX="heroku-18/" \
+    DEBIAN_FRONTEND=noninteractive \
+    STACK="heroku-18"
+
+RUN apt-get update && apt-get install --no-install-recommends -y python-pip-whl=9.0.1-2 python-pip=9.0.1-2 python-setuptools python-wheel libsqlite3-dev && rm -rf /var/lib/apt/lists/*
+
+COPY requirements.txt /app/
+RUN pip install --disable-pip-version-check --no-cache-dir -r /app/requirements.txt
+
+COPY . /app

builds/libraries/autoconf

@@ -1,15 +0,0 @@
-#!/usr/bin/env bash
-# Build Path: /app/.heroku/python/
-
-OUT_PREFIX=$1
-
-echo "Building autoconf..."
-
-
-SOURCE_TARBALL='http://ftp.gnu.org/gnu/autoconf/autoconf-2.68.tar.gz'
-curl -L $SOURCE_TARBALL | tar xz
-
-cd autoconf-2.68
-./configure --prefix=$OUT_PREFIX
-make
-make install

builds/libraries/libffi

@@ -1,23 +0,0 @@
-#!/usr/bin/env bash
-# Build Path: /app/.heroku/python/
-
-OUT_PREFIX=$1
-
-# Use new path, containing autoconf.
-export PATH="/app/.heroku/python/bin/:$PATH"
-hash -r
-
-
-echo "Building libffi..."
-
-SOURCE_TARBALL='http://cl.ly/2s1t1u3v0N0I/download/libffi-3.1.tar'
-
-curl -L $SOURCE_TARBALL | tar x
-
-cd libffi-3.1
-./configure --prefix=$OUT_PREFIX --disable-static &&
-make
-make install
-
-# Cleanup
-cd ..

builds/libraries/sqlite

@@ -3,10 +3,10 @@
 
 OUT_PREFIX=$1
 
-echo "Building SQLite..."
+echo "Building SQLite…"
 
 
-SOURCE_TARBALL='http://www.sqlite.org/sqlite-autoconf-3070900.tar.gz'
+SOURCE_TARBALL='https://www.sqlite.org/sqlite-autoconf-3070900.tar.gz'
 
 curl $SOURCE_TARBALL | tar xz
 # jx

builds/libraries/vendor/gdal

@@ -0,0 +1,24 @@
+#!/usr/bin/env bash
+# Build Path: /app/.heroku/vendor/
+
+OUT_PREFIX=$1
+
+# Use new path, containing autoconf.
+export PATH="/app/.heroku/python/bin/:$PATH"
+hash -r
+
+
+echo "Building gdal…"
+
+VERSION="2.2.1"
+SOURCE_TARBALL="http://download.osgeo.org/gdal/${VERSION}/gdal-${VERSION}.tar.gz"
+
+curl -L $SOURCE_TARBALL | tar zx
+
+pushd "gdal-${VERSION}"
+./configure --prefix=$OUT_PREFIX --enable-static=no  &&
+make
+make install
+
+# Cleanup
+popd

builds/libraries/vendor/geos

@@ -0,0 +1,25 @@
+#!/usr/bin/env bash
+# Build Path: /app/.heroku/vendor/
+
+OUT_PREFIX=$1
+
+# Use new path, containing autoconf.
+export PATH="/app/.heroku/python/bin/:$PATH"
+hash -r
+
+
+echo "Building geos…"
+
+VERSION=3.6.2
+
+SOURCE_TARBALL="http://download.osgeo.org/geos/geos-${VERSION}.tar.bz2"
+
+curl -L $SOURCE_TARBALL | tar xj
+
+pushd "geos-${VERSION}"
+./configure --prefix=$OUT_PREFIX --enable-static=no &&
+make
+make install
+
+# Cleanup
+popd

builds/libraries/vendor/libffi

@@ -3,12 +3,17 @@
 
 OUT_PREFIX=$1
 
+# Skip the build for heroku-16.
+if [[ $S3_PREFIX == "heroku-16" ]]; then
+    exit 0
+fi
+
 # Use new path, containing autoconf.
 export PATH="/app/.heroku/python/bin/:$PATH"
 hash -r
 
 
-echo "Building libffi..."
+echo "Building libffi…"
 
 SOURCE_TARBALL='ftp://sourceware.org/pub/libffi/libffi-3.1.tar.gz'
 

builds/libraries/vendor/libmemcache

@@ -3,6 +3,11 @@
 
 OUT_PREFIX=$1
 
+# Skip the build for heroku-16.
+if [[ $S3_PREFIX == "heroku-16" ]]; then
+    exit 0
+fi
+
 # fail hard
 set -o pipefail
 # fail harder
@@ -15,7 +20,7 @@ dep_archive_name=${dep_dirname}.tar.gz
 dep_url=https://launchpad.net/libmemcached/1.0/${dep_version}/+download/${dep_archive_name}
 
 # SASL Support.
-echo "-----> Building cyrus-sasl 2.1.26..."
+echo "-----> Building cyrus-sasl 2.1.26…"
 
 curl -LO ftp://ftp.cyrusimap.org/cyrus-sasl/cyrus-sasl-2.1.26.tar.gz
 # FTP doesn't play well with piping into tar xz
@@ -28,7 +33,7 @@ make -s -j 9
 make install -s
 popd
 
-echo "-----> Building libmemcached ${dep_version}..."
+echo "-----> Building libmemcached ${dep_version}…"
 
 curl -L ${dep_url} | tar xz
 pushd ${dep_dirname}

builds/libraries/vendor/proj

@@ -0,0 +1,24 @@
+#!/usr/bin/env bash
+# Build Path: /app/.heroku/vendor/
+
+OUT_PREFIX=$1
+
+# Use new path, containing autoconf.
+export PATH="/app/.heroku/python/bin/:$PATH"
+hash -r
+
+
+echo "Building gdal…"
+
+VERSION=4.9.3
+SOURCE_TARBALL="http://download.osgeo.org/proj/proj-${VERSION}.tar.gz"
+
+curl -L $SOURCE_TARBALL | tar zx
+
+pushd "proj-${VERSION}"
+./configure --prefix=$OUT_PREFIX --enable-static=no
+make
+make install
+
+# Cleanup
+popd

builds/runtimes/pypy

@@ -0,0 +1,22 @@
+#!/usr/bin/env bash
+
+# fail hard
+set -o pipefail
+# fail harder
+set -eu
+
+OUT_PREFIX=$1
+
+dep_formula=${0#$WORKSPACE_DIR/} # this is the original script, e.g. pypy-5.3.1
+dep_name=$(basename $BASH_SOURCE) # this is us
+dep_version=${dep_formula##*"/${dep_name}-"} # "subtract" our name from full version name
+dep_package=${dep_name}2-v${dep_version} # it's always "pypy2-…"
+dep_dirname=${dep_package}-linux64
+dep_archive_name=${dep_dirname}.tar.bz2
+dep_url=https://bitbucket.org/pypy/pypy/downloads/${dep_archive_name}
+
+echo "Building PyPy…"
+
+curl -L "${dep_url}" | tar jx -C "${OUT_PREFIX}" --strip-components 1 # extract to $OUT_PREFIX, drop the first directory level, which is the archive name
+
+ln "$OUT_PREFIX/bin/pypy" "$OUT_PREFIX/bin/python"

builds/runtimes/pypy-1.7

@@ -1,12 +0,0 @@
-#!/usr/bin/env bash
-# Build Path: /app/.heroku/python/
-# Build Deps: libraries/sqlite
-
-OUT_PREFIX=$1
-
-echo "Building PyPy..."
-SOURCE_TARBALL='https://bitbucket.org/pypy/pypy/downloads/pypy-1.7-linux64.tar.bz2'
-curl -L $SOURCE_TARBALL | tar jx
-cp -R pypy-1.7/* $OUT_PREFIX
-
-ln $OUT_PREFIX/bin/pypy $OUT_PREFIX/bin/python

builds/runtimes/pypy-1.8

@@ -1,12 +0,0 @@
-#!/usr/bin/env bash
-# Build Path: /app/.heroku/python/
-# Build Deps: libraries/sqlite
-
-OUT_PREFIX=$1
-
-echo "Building PyPy..."
-SOURCE_TARBALL='https://bitbucket.org/pypy/pypy/downloads/pypy-1.8-linux64.tar.bz2'
-curl -L $SOURCE_TARBALL | tar jx
-cp -R pypy-1.8/* $OUT_PREFIX
-
-ln $OUT_PREFIX/bin/pypy $OUT_PREFIX/bin/python

builds/runtimes/pypy-1.9

@@ -1,12 +0,0 @@
-#!/usr/bin/env bash
-# Build Path: /app/.heroku/python/
-# Build Deps: libraries/sqlite
-
-OUT_PREFIX=$1
-
-echo "Building PyPy..."
-SOURCE_TARBALL='https://bitbucket.org/pypy/pypy/downloads/pypy-1.9-linux64.tar.bz2'
-curl -L $SOURCE_TARBALL | tar jx
-cp -R pypy-1.9/* $OUT_PREFIX
-
-ln $OUT_PREFIX/bin/pypy $OUT_PREFIX/bin/python

builds/runtimes/pypy-2.0

@@ -1,14 +0,0 @@
-#!/usr/bin/env bash
-# Build Path: /app/.heroku/python/
-# Build Deps: libraries/sqlite
-
-# NOTICE: This formula only works for the cedar-14 stack, not cedar.
-
-OUT_PREFIX=$1
-
-echo "Building PyPy..."
-SOURCE_TARBALL='https://bitbucket.org/pypy/pypy/downloads/pypy-2.0-linux64.tar.bz2'
-curl -L $SOURCE_TARBALL | tar jx
-cp -R pypy-2.0/* $OUT_PREFIX
-
-ln $OUT_PREFIX/bin/pypy $OUT_PREFIX/bin/python

builds/runtimes/pypy-2.0.1

@@ -1,14 +0,0 @@
-#!/usr/bin/env bash
-# Build Path: /app/.heroku/python/
-# Build Deps: libraries/sqlite
-
-# NOTICE: This formula only works for the cedar-14 stack, not cedar.
-
-OUT_PREFIX=$1
-
-echo "Building PyPy..."
-SOURCE_TARBALL='https://bitbucket.org/pypy/pypy/downloads/pypy-2.0.1-linux64.tar.bz2'
-curl -L $SOURCE_TARBALL | tar jx
-cp -R pypy-2.0.1/* $OUT_PREFIX
-
-ln $OUT_PREFIX/bin/pypy $OUT_PREFIX/bin/python

builds/runtimes/pypy-2.0.2

@@ -1,14 +0,0 @@
-#!/usr/bin/env bash
-# Build Path: /app/.heroku/python/
-# Build Deps: libraries/sqlite
-
-# NOTICE: This formula only works for the cedar-14 stack, not cedar.
-
-OUT_PREFIX=$1
-
-echo "Building PyPy..."
-SOURCE_TARBALL='https://bitbucket.org/pypy/pypy/downloads/pypy-2.0.2-linux64.tar.bz2'
-curl -L $SOURCE_TARBALL | tar jx
-cp -R pypy-2.0.2/* $OUT_PREFIX
-
-ln $OUT_PREFIX/bin/pypy $OUT_PREFIX/bin/python

builds/runtimes/pypy-2.1

@@ -1,14 +0,0 @@
-#!/usr/bin/env bash
-# Build Path: /app/.heroku/python/
-# Build Deps: libraries/sqlite
-
-# NOTICE: This formula only works for the cedar-14 stack, not cedar.
-
-OUT_PREFIX=$1
-
-echo "Building PyPy..."
-SOURCE_TARBALL='https://bitbucket.org/pypy/pypy/downloads/pypy-2.1-linux64.tar.bz2'
-curl -L $SOURCE_TARBALL | tar jx
-cp -R pypy-2.1/* $OUT_PREFIX
-
-ln $OUT_PREFIX/bin/pypy $OUT_PREFIX/bin/python

builds/runtimes/pypy-2.2

@@ -1,14 +0,0 @@
-#!/usr/bin/env bash
-# Build Path: /app/.heroku/python/
-# Build Deps: libraries/sqlite
-
-# NOTICE: This formula only works for the cedar-14 stack, not cedar.
-
-OUT_PREFIX=$1
-
-echo "Building PyPy..."
-SOURCE_TARBALL='https://bitbucket.org/pypy/pypy/downloads/pypy-2.2-linux64.tar.bz2'
-curl -L $SOURCE_TARBALL | tar jx
-cp -R pypy-2.2-linux64/* $OUT_PREFIX
-
-ln $OUT_PREFIX/bin/pypy $OUT_PREFIX/bin/python

builds/runtimes/pypy-2.2.1

@@ -1,14 +0,0 @@
-#!/usr/bin/env bash
-# Build Path: /app/.heroku/python/
-# Build Deps: libraries/sqlite
-
-# NOTICE: This formula only works for the cedar-14 stack, not cedar.
-
-OUT_PREFIX=$1
-
-echo "Building PyPy..."
-SOURCE_TARBALL='https://bitbucket.org/pypy/pypy/downloads/pypy-2.2.1-linux64.tar.bz2'
-curl -L $SOURCE_TARBALL | tar jx
-cp -R pypy-2.2.1-linux64/* $OUT_PREFIX
-
-ln $OUT_PREFIX/bin/pypy $OUT_PREFIX/bin/python

builds/runtimes/pypy-2.3

@@ -1,14 +0,0 @@
-#!/usr/bin/env bash
-# Build Path: /app/.heroku/python/
-# Build Deps: libraries/sqlite, libraries/libffi
-
-# NOTICE: This formula only works for the cedar-14 stack, not cedar.
-
-OUT_PREFIX=$1
-
-echo "Building PyPy..."
-SOURCE_TARBALL='https://bitbucket.org/pypy/pypy/downloads/pypy-2.3-linux64.tar.bz2'
-curl -L $SOURCE_TARBALL | tar jx
-cp -R pypy-2.3-linux64/* $OUT_PREFIX
-
-ln $OUT_PREFIX/bin/pypy $OUT_PREFIX/bin/python

builds/runtimes/pypy-2.3.1

@@ -1,14 +0,0 @@
-#!/usr/bin/env bash
-# Build Path: /app/.heroku/python/
-# Build Deps: libraries/sqlite
-
-# NOTICE: This formula only works for the cedar-14 stack, not cedar.
-
-OUT_PREFIX=$1
-
-echo "Building PyPy..."
-SOURCE_TARBALL='https://bitbucket.org/pypy/pypy/downloads/pypy-2.3.1-linux64.tar.bz2'
-curl -L $SOURCE_TARBALL | tar jx
-cp -R pypy-2.3.1-linux64/* $OUT_PREFIX
-
-ln $OUT_PREFIX/bin/pypy $OUT_PREFIX/bin/python

builds/runtimes/pypy-2.4.0

@@ -1,14 +0,0 @@
-#!/usr/bin/env bash
-# Build Path: /app/.heroku/python/
-# Build Deps: libraries/sqlite
-
-# NOTICE: This formula only works for the cedar-14 stack, not cedar.
-
-OUT_PREFIX=$1
-
-echo "Building PyPy..."
-SOURCE_TARBALL='https://bitbucket.org/pypy/pypy/downloads/pypy-2.4.0-linux64.tar.bz2'
-curl -L $SOURCE_TARBALL | tar jx
-cp -R pypy-2.4.0-linux64/* $OUT_PREFIX
-
-ln $OUT_PREFIX/bin/pypy $OUT_PREFIX/bin/python

builds/runtimes/pypy-5.3.1

@@ -0,0 +1,5 @@
+#!/usr/bin/env bash
+# Build Path: /app/.heroku/python/
+# Build Deps: libraries/sqlite
+
+source $(dirname $0)/pypy

builds/runtimes/pypy-5.6.0

@@ -0,0 +1,5 @@
+#!/usr/bin/env bash
+# Build Path: /app/.heroku/python/
+# Build Deps: libraries/sqlite
+
+source $(dirname $0)/pypy

builds/runtimes/pypy-5.7.0

@@ -0,0 +1,5 @@
+#!/usr/bin/env bash
+# Build Path: /app/.heroku/python/
+# Build Deps: libraries/sqlite
+
+source $(dirname $0)/pypy

builds/runtimes/pypy-5.7.1

@@ -0,0 +1,5 @@
+#!/usr/bin/env bash
+# Build Path: /app/.heroku/python/
+# Build Deps: libraries/sqlite
+
+source $(dirname $0)/pypy

builds/runtimes/pypy-5.8.0

@@ -0,0 +1,5 @@
+#!/usr/bin/env bash
+# Build Path: /app/.heroku/python/
+# Build Deps: libraries/sqlite
+
+source $(dirname $0)/pypy

builds/runtimes/pypy2.7

@@ -0,0 +1,23 @@
+#!/usr/bin/env bash
+
+# fail hard
+set -o pipefail
+# fail harder
+set -eu
+
+OUT_PREFIX=$1
+
+dep_formula=${0#$WORKSPACE_DIR/} # this is the original script, e.g. pypy-5.3.1
+dep_name=$(basename $BASH_SOURCE) # this is us
+dep_version=${dep_formula##*"/${dep_name}-"} # "subtract" our name from full version name
+dep_package=${dep_name}-v${dep_version} # it's always "pypy2-…"
+dep_dirname=${dep_package}-linux64
+dep_archive_name=${dep_dirname}.tar.bz2
+dep_url=https://bitbucket.org/pypy/pypy/downloads/${dep_archive_name}
+
+echo "Building PyPy…"
+echo "${dep_url}"
+
+curl -L "${dep_url}" | tar jx -C "${OUT_PREFIX}" --strip-components 1 # extract to $OUT_PREFIX, drop the first directory level, which is the archive name
+
+ln "$OUT_PREFIX/bin/pypy" "$OUT_PREFIX/bin/python"

builds/runtimes/pypy2.7-7.2.0

@@ -0,0 +1,4 @@
+#!/usr/bin/env bash
+# Build Path: /app/.heroku/python/
+
+source $(dirname $0)/pypy2.7

builds/runtimes/pypy3

@@ -0,0 +1,22 @@
+#!/usr/bin/env bash
+
+# fail hard
+set -o pipefail
+# fail harder
+set -eu
+
+OUT_PREFIX=$1
+
+dep_formula=${0#$WORKSPACE_DIR/} # this is the original script, e.g. pypy-5.3.1
+dep_name=$(basename $BASH_SOURCE) # this is us
+dep_version=${dep_formula##*"/${dep_name}-"} # "subtract" our name from full version name
+dep_package=${dep_name}${dep_version_prefix:-}-v${dep_version}${dep_version_suffix:-}
+dep_dirname=${dep_package}-linux64
+dep_archive_name=${dep_dirname}.tar.bz2
+dep_url=https://bitbucket.org/pypy/pypy/downloads/${dep_archive_name}
+
+echo "Building PyPy3…"
+
+curl -L "${dep_url}" | tar jx -C "${OUT_PREFIX}" --strip-components 1 # extract to $OUT_PREFIX, drop the first directory level, which is the archive name
+
+ln "$OUT_PREFIX/bin/pypy3" "$OUT_PREFIX/bin/python"

builds/runtimes/pypy3-2.3.1

@@ -1,14 +0,0 @@
-#!/usr/bin/env bash
-# Build Path: /app/.heroku/python/
-# Build Deps: libraries/sqlite
-
-# NOTICE: This formula only works for the cedar-14 stack, not cedar.
-
-OUT_PREFIX=$1
-
-echo "Building PyPy..."
-SOURCE_TARBALL='https://bitbucket.org/pypy/pypy/downloads/pypy3-2.3.1-linux64.tar.bz2'
-curl -L $SOURCE_TARBALL | tar jx
-cp -R pypy3-2.3.1-linux64/* $OUT_PREFIX
-
-ln $OUT_PREFIX/bin/pypy $OUT_PREFIX/bin/python

builds/runtimes/pypy3-2.4.0

@@ -2,13 +2,4 @@
 # Build Path: /app/.heroku/python/
 # Build Deps: libraries/sqlite
 
-# NOTICE: This formula only works for the cedar-14 stack, not cedar.
+source $(dirname $0)/pypy3
-
-OUT_PREFIX=$1
-
-echo "Building PyPy..."
-SOURCE_TARBALL='https://bitbucket.org/pypy/pypy/downloads/pypy3-2.4.0-linux64.tar.bz2'
-curl -L $SOURCE_TARBALL | tar jx
-cp -R pypy3-2.4.0-linux64/* $OUT_PREFIX
-
-ln $OUT_PREFIX/bin/pypy3 $OUT_PREFIX/bin/python

builds/runtimes/pypy3-5.5.0

@@ -0,0 +1,8 @@
+#!/usr/bin/env bash
+# Build Path: /app/.heroku/python/
+# Build Deps: libraries/sqlite
+
+# version pypy3-5.5.0 is really called pypy3.3-v5.5.0-alpha
+dep_version_prefix=".3"
+dep_version_suffix="-alpha"
+source $(dirname $0)/pypy3

builds/runtimes/pypy3-5.7.1

@@ -0,0 +1,5 @@
+#!/usr/bin/env bash
+# Build Path: /app/.heroku/python/
+# Build Deps: libraries/sqlite
+
+source $(dirname $0)/pypy3

builds/runtimes/pypy3-5.8.0

@@ -0,0 +1,5 @@
+#!/usr/bin/env bash
+# Build Path: /app/.heroku/python/
+# Build Deps: libraries/sqlite
+
+source $(dirname $0)/pypy3

builds/runtimes/pypy3.6

@@ -0,0 +1,23 @@
+#!/usr/bin/env bash
+
+# fail hard
+set -o pipefail
+# fail harder
+set -eu
+
+OUT_PREFIX=$1
+
+dep_formula=${0#$WORKSPACE_DIR/} # this is the original script, e.g. pypy-5.3.1
+dep_name=$(basename $BASH_SOURCE) # this is us
+dep_version=${dep_formula##*"/${dep_name}-"} # "subtract" our name from full version name
+dep_package=${dep_name}${dep_version_prefix:-}-v${dep_version}${dep_version_suffix:-}
+dep_dirname=${dep_package}-linux64
+dep_archive_name=${dep_dirname}.tar.bz2
+dep_url=https://bitbucket.org/pypy/pypy/downloads/${dep_archive_name}
+
+echo "Building PyPy3…"
+echo "${dep_url}"
+
+curl -L "${dep_url}" | tar jx -C "${OUT_PREFIX}" --strip-components 1 # extract to $OUT_PREFIX, drop the first directory level, which is the archive name
+
+ln "$OUT_PREFIX/bin/pypy3" "$OUT_PREFIX/bin/python"

builds/runtimes/pypy3.6-7.2.0

@@ -0,0 +1,4 @@
+#!/usr/bin/env bash
+# Build Path: /app/.heroku/python/
+
+source $(dirname $0)/pypy3.6

builds/runtimes/python-2.4.4

@@ -1,18 +0,0 @@
-#!/usr/bin/env bash
-# Build Path: /app/.heroku/python/
-# Build Deps: libraries/sqlite
-
-OUT_PREFIX=$1
-
-# Protect 2.4 builds from parent Python (causes segfault during build).
-unset LANG PYTHONHOME PYTHONPATH
-
-echo "Building Python..."
-SOURCE_TARBALL='http://python.org/ftp/python/2.4.4/Python-2.4.4.tgz'
-curl -L $SOURCE_TARBALL | tar xz
-mv Python-2.4.4 src
-cd src
-
-./configure --prefix=$OUT_PREFIX
-make
-make install

builds/runtimes/python-2.4.5

@@ -1,18 +0,0 @@
-#!/usr/bin/env bash
-# Build Path: /app/.heroku/python/
-# Build Deps: libraries/sqlite
-
-OUT_PREFIX=$1
-
-# Protect 2.4 builds from parent Python (causes segfault during build).
-unset LANG PYTHONHOME PYTHONPATH
-
-echo "Building Python..."
-SOURCE_TARBALL='http://python.org/ftp/python/2.4.5/Python-2.4.5.tgz'
-curl -L $SOURCE_TARBALL | tar xz
-mv Python-2.4.5 src
-cd src
-
-./configure --prefix=$OUT_PREFIX
-make
-make install

builds/runtimes/python-2.4.6

@@ -1,18 +0,0 @@
-#!/usr/bin/env bash
-# Build Path: /app/.heroku/python/
-# Build Deps: libraries/sqlite
-
-OUT_PREFIX=$1
-
-# Protect 2.4 builds from parent Python (causes segfault during build).
-unset LANG PYTHONHOME PYTHONPATH
-
-echo "Building Python..."
-SOURCE_TARBALL='http://python.org/ftp/python/2.4.6/Python-2.4.6.tgz'
-curl -L $SOURCE_TARBALL | tar xz
-mv Python-2.4.6 src
-cd src
-
-./configure --prefix=$OUT_PREFIX
-make
-make install

builds/runtimes/python-2.5.0

@@ -1,18 +0,0 @@
-#!/usr/bin/env bash
-# Build Path: /app/.heroku/python/
-# Build Deps: libraries/sqlite
-
-OUT_PREFIX=$1
-
-# Protect 2.5 builds from parent Python (causes segfault during build).
-unset LANG PYTHONHOME PYTHONPATH
-
-echo "Building Python..."
-SOURCE_TARBALL='http://python.org/ftp/python/2.5/Python-2.5.tgz'
-curl -L $SOURCE_TARBALL | tar xz
-mv Python-2.5 src
-cd src
-
-./configure --prefix=$OUT_PREFIX
-make
-make install

builds/runtimes/python-2.5.1

@@ -1,18 +0,0 @@
-#!/usr/bin/env bash
-# Build Path: /app/.heroku/python/
-# Build Deps: libraries/sqlite
-
-OUT_PREFIX=$1
-
-# Protect 2.5 builds from parent Python (causes segfault during build).
-unset LANG PYTHONHOME PYTHONPATH
-
-echo "Building Python..."
-SOURCE_TARBALL='http://python.org/ftp/python/2.5.1/Python-2.5.1.tgz'
-curl -L $SOURCE_TARBALL | tar xz
-mv Python-2.5.1 src
-cd src
-
-./configure --prefix=$OUT_PREFIX
-make
-make install

builds/runtimes/python-2.5.2

@@ -1,18 +0,0 @@
-#!/usr/bin/env bash
-# Build Path: /app/.heroku/python/
-# Build Deps: libraries/sqlite
-
-OUT_PREFIX=$1
-
-# Protect 2.5 builds from parent Python (causes segfault during build).
-unset LANG PYTHONHOME PYTHONPATH
-
-echo "Building Python..."
-SOURCE_TARBALL='http://python.org/ftp/python/2.5.2/Python-2.5.2.tgz'
-curl -L $SOURCE_TARBALL | tar xz
-mv Python-2.5.2 src
-cd src
-
-./configure --prefix=$OUT_PREFIX
-make
-make install

builds/runtimes/python-2.5.3

@@ -1,18 +0,0 @@
-#!/usr/bin/env bash
-# Build Path: /app/.heroku/python/
-# Build Deps: libraries/sqlite
-
-OUT_PREFIX=$1
-
-# Protect 2.5 builds from parent Python (causes segfault during build).
-unset LANG PYTHONHOME PYTHONPATH
-
-echo "Building Python..."
-SOURCE_TARBALL='http://python.org/ftp/python/2.5.3/Python-2.5.3.tgz'
-curl -L $SOURCE_TARBALL | tar xz
-mv Python-2.5.3 src
-cd src
-
-./configure --prefix=$OUT_PREFIX
-make
-make install

builds/runtimes/python-2.5.4

@@ -1,18 +0,0 @@
-#!/usr/bin/env bash
-# Build Path: /app/.heroku/python/
-# Build Deps: libraries/sqlite
-
-OUT_PREFIX=$1
-
-# Protect 2.5 builds from parent Python (causes segfault during build).
-unset LANG PYTHONHOME PYTHONPATH
-
-echo "Building Python..."
-SOURCE_TARBALL='http://python.org/ftp/python/2.5.4/Python-2.5.4.tgz'
-curl -L $SOURCE_TARBALL | tar xz
-mv Python-2.5.4 src
-cd src
-
-./configure --prefix=$OUT_PREFIX
-make
-make install

builds/runtimes/python-2.5.5

@@ -1,18 +0,0 @@
-#!/usr/bin/env bash
-# Build Path: /app/.heroku/python/
-# Build Deps: libraries/sqlite
-
-OUT_PREFIX=$1
-
-# Protect 2.6 builds from parent Python (causes segfault during build).
-unset LANG PYTHONHOME PYTHONPATH
-
-echo "Building Python..."
-SOURCE_TARBALL='http://python.org/ftp/python/2.5.5/Python-2.5.5.tgz'
-curl -L $SOURCE_TARBALL | tar xz
-mv Python-2.5.5 src
-cd src
-
-./configure --prefix=$OUT_PREFIX
-make
-make install

builds/runtimes/python-2.5.6

@@ -1,18 +0,0 @@
-#!/usr/bin/env bash
-# Build Path: /app/.heroku/python/
-# Build Deps: libraries/sqlite
-
-OUT_PREFIX=$1
-
-# Protect 2.5 builds from parent Python (causes segfault during build).
-unset LANG PYTHONHOME PYTHONPATH
-
-echo "Building Python..."
-SOURCE_TARBALL='http://python.org/ftp/python/2.5.6/Python-2.5.6.tgz'
-curl -L $SOURCE_TARBALL | tar xz
-mv Python-2.5.6 src
-cd src
-
-./configure --prefix=$OUT_PREFIX
-make
-make install

builds/runtimes/python-2.6.0

@@ -1,20 +0,0 @@
-#!/usr/bin/env bash
-# Build Path: /app/.heroku/python/
-# Build Deps: libraries/sqlite
-
-# NOTICE: This formula only works for the cedar stack, not cedar-14.
-
-OUT_PREFIX=$1
-
-# Protect 2.6 builds from parent Python (causes segfault during build).
-unset LANG PYTHONHOME PYTHONPATH
-
-echo "Building Python..."
-SOURCE_TARBALL='http://www.python.org/ftp/python/2.6/Python-2.6.tar.bz2'
-curl -L $SOURCE_TARBALL | tar jx
-mv Python-2.6 src
-cd src
-
-./configure --prefix=$OUT_PREFIX --enable-shared
-make
-make install

builds/runtimes/python-2.6.1

@@ -1,20 +0,0 @@
-#!/usr/bin/env bash
-# Build Path: /app/.heroku/python/
-# Build Deps: libraries/sqlite
-
-# NOTICE: This formula only works for the cedar stack, not cedar-14.
-
-OUT_PREFIX=$1
-
-# Protect 2.6 builds from parent Python (causes segfault during build).
-unset LANG PYTHONHOME PYTHONPATH
-
-echo "Building Python..."
-SOURCE_TARBALL='http://python.org/ftp/python/2.6.1/Python-2.6.1.tgz'
-curl -L $SOURCE_TARBALL | tar xz
-mv Python-2.6.1 src
-cd src
-
-./configure --prefix=$OUT_PREFIX --enable-shared
-make
-make install

builds/runtimes/python-2.6.2

@@ -1,18 +0,0 @@
-#!/usr/bin/env bash
-# Build Path: /app/.heroku/python/
-# Build Deps: libraries/sqlite
-
-OUT_PREFIX=$1
-
-# Protect 2.6 builds from parent Python (causes segfault during build).
-unset LANG PYTHONHOME PYTHONPATH
-
-echo "Building Python..."
-SOURCE_TARBALL='http://python.org/ftp/python/2.6.2/Python-2.6.2.tgz'
-curl -L $SOURCE_TARBALL | tar xz
-mv Python-2.6.2 src
-cd src
-
-./configure --prefix=$OUT_PREFIX --enable-shared
-make
-make install