Merge pull request #769 from heroku/pip-pipenv-pin

Pin pip version used by pipenv
changelog update
2026-06-05 23:10:16 +00:00 · 2018-10-11 14:50:52 -05:00 · 2018-10-10 09:23:54 -05:00 · 2018-10-09 14:46:49 -05:00 · 2018-10-08 16:01:45 -05:00 · 2018-10-05 13:48:22 -05:00
125 changed files with 24444 additions and 20209 deletions
@@ -0,0 +1 @@
+* @heroku/languages
@@ -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 :-)
+-->
@@ -1,3 +1,9 @@
 *.pyc
 site
 .DS_Store
+
+/.envrc
+repos/*
+
+#Venv
+buildpack/*
@@ -1,9 +1,39 @@
-language: bash
+language: ruby
+dist: trusty
 sudo: required
-services:
-  - docker
-# install: docker pull heroku/cedar:14
-script: ./tests.sh
+rvm:
+- 2.4.4
+before_script:
+  - gem install bundler -v 1.16.2
+  - bundle exec rake hatchet:setup_travis
+before_install:
+  - sudo bash etc/ci-setup.sh
+jobs:
+  include:
+  - stage: Bash linting (shellcheck)
+    sudo: false
+    before_install:
+    - wget -c https://goo.gl/ZzKHFv -O - | tar -xvJ -C /tmp/
+    - PATH="/tmp/shellcheck-latest:$PATH"
+    script: make check
+  - stage: Stack Unit Tests
+    services: docker
+    env: STACK=heroku-18
+    script: "./tests.sh"
+  - stage: Stack Unit Tests
+    services: docker
+    env: STACK=heroku-16
+    script: "./tests.sh"
+  - stage: Stack Unit Tests
+    services: docker
+    env: STACK=cedar-14
+    script: "./tests.sh"
+  - stage: Hatchet Integration
+    script: "bundle exec rspec"
 env:
-  - STACK=heroku-16
-  - STACK=cedar-14
+  global:
+  - HATCHET_RETRIES=3
+  - IS_RUNNING_ON_CI=true
+  - HATCHET_APP_LIMIT=5
+  - secure: yjtlPE5FbVxTKnjUy/tZUBgSEf4qADD3QOxtgziuid73S0U/1IEXlMGFULsQzIjtlHKmHeywZqpVVEpthIH4RuT7uoX1Pb7SSM/g0T8fT3VoEFbFK1uYl0oZQbUS4Klxv9tPiumj8if3m6ULEGIz1X0wZcMOC0tMLwVCnwmap0E=
+  - secure: ZeFTHWwnpIKE9nAqs88ocmiQh7bKce84lilGm5J23nf3N6V4wNyLwqlkvsM008WGBCaOg9AUx7ZunasT0ANsR5gLP3eV2UUg7ILdRgV2Gy13eNRFheC4PHdN92RqQ3aKoqlIv2K999xlhVjod0NzhkQQXB6PddfQINbuU7ks6As=
@@ -1,18 +1,161 @@
 # Python Buildpack Changelog

+# 141 (2018-10-10)
+
+Switch to cautious upgrade for Pipenv install to ensure the pinned pip version
+is used with Pipenv
+
+# 140 (2018-10-09)
+
+Add support for detecting SLUGIFY_USES_TEXT_UNIDECODE, which is required to
+install Apache Airflow version 1.10 or higher.
+
+# 139 (2018-10-08)
+
+Improvements to Python install messaging
+
+# 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.

-# 109
-
-Fix output for collectstatic step.
-
 # 108

-Updated setuptools.
+Fix output for collectstatic step.

 # 107

@@ -0,0 +1,13 @@
+FROM heroku/heroku:18-build
+
+WORKDIR /app
+ENV WORKSPACE_DIR="/app/builds" \
+    S3_BUCKET="lang-python" \
+    S3_PREFIX="heroku-18/"
+
+RUN apt-get update && apt-get install -y python-pip && 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
@@ -0,0 +1,6 @@
+source "https://rubygems.org"
+
+gem "rspec"
+gem "heroku_hatchet"
+gem "rspec-retry"
+gem "rake"
@@ -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 (1.0.5)
+    diff-lcs (1.3)
+    erubis (2.7.0)
+    excon (0.62.0)
+    heroics (0.0.24)
+      erubis (~> 2.0)
+      excon
+      moneta
+      multi_json (>= 1.9.2)
+    heroku_hatchet (4.0.2)
+      excon (~> 0)
+      minitest-retry (~> 0.1.9)
+      platform-api (~> 2)
+      repl_runner (~> 0.0.3)
+      rrrretry (~> 1)
+      thor (~> 0)
+      threaded (~> 0)
+    i18n (1.1.0)
+      concurrent-ruby (~> 1.0)
+    minitest (5.11.3)
+    minitest-retry (0.1.9)
+      minitest (>= 5.0)
+    moneta (0.8.1)
+    multi_json (1.13.1)
+    platform-api (2.1.0)
+      heroics (~> 0.0.23)
+      moneta (~> 0.8.1)
+    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 (0.20.0)
+    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
@@ -1,7 +1,12 @@
 # These targets are not files
 .PHONY: tests

-test: test-cedar-14
+test: test-heroku-16
+
+check:
+	@shellcheck -x bin/compile bin/detect bin/release bin/test-compile bin/utils bin/warnings
+	@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)..."
@@ -13,6 +18,11 @@ test-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;'
 	@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;'
+	@echo ""
+
 buildenv-heroku-16:
 	@echo "Creating build environment (heroku-16)..."
 	@echo
@@ -0,0 +1,9 @@
+[[source]]
+url = "https://pypi.python.org/simple"
+verify_ssl = true
+name = "pypi"
+
+[dev-packages]
+
+[packages]
+"bob-builder" = "==0.0.13"
@@ -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": {}
+}
@@ -4,11 +4,11 @@

 [![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, powered by [pip](https://pip.pypa.io/) and other excellent software.
+This is the official [Heroku buildpack](https://devcenter.heroku.com/articles/buildpacks) for Python apps, powered by [Pipenv](http://docs.pipenv.org/), [pip](https://pip.pypa.io/) and other excellent software.

 Recommended web frameworks include **Django** and **Flask**. 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.

-Some Python packages with obscure C dependencies are [not compatible](https://devcenter.heroku.com/articles/python-c-deps).
+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
 ----------------
@@ -16,24 +16,22 @@ See it in Action
 Deploying a Python application couldn't be easier:

    $ ls
-    Procfile  requirements.txt  web.py
+    Pipfile		Pipfile.lock	Procfile	web.py

    $ heroku create --buildpack heroku/python

    $ git push heroku master
-    ...
+    …
    -----> Python app detected
-    -----> Installing python-3.6.2
-         $ pip install -r requirements.txt
-           Collecting requests (from -r requirements.txt (line 1))
-             Downloading requests-2.12.4-py2.py3-none-any.whl (576KB)
-           Installing collected packages: requests
-           Successfully installed requests-2.12.4
-
+    -----> Installing python-3.6.6
+    -----> Installing pip
+    -----> Installing requirements with Pipenv 2018.5.18…
+           ...
+           Installing dependencies from Pipfile…
    -----> Discovering process types
           Procfile declares types -> (none)

-A `requirements.txt` file must be present at the root of your application's repository.
+A `Pipfile` or `requirements.txt` must be present at the root of your application's repository.

 You can also specify the latest production release of this buildpack for upcoming builds of an existing application:

@@ -43,14 +41,23 @@ You can also specify the latest production release of this buildpack for upcomin
 Specify a Python Runtime
 ------------------------

-Specific versions of the Python runtime can be specified with a `runtime.txt` file:
+Specific versions of the Python runtime can be specified in your `Pipfile`:
+
+    [requires]
+    python_version = "2.7"
+
+Or, more specifically:
+
+    [requires]
+    python_full_version = "2.7.15"
+
+Or, with a `runtime.txt` file:

    $ cat runtime.txt
-    python-2.7.13
+    python-2.7.15

 Runtime options include:

- `python-3.6.2`
- `python-2.7.13`
- `pypy-5.7.1` (unsupported, experimental)
- `pypy3-5.5.1` (unsupported, experimental)
+- `python-3.7.0`
+- `python-3.6.6`
+- `python-2.7.15`
@@ -0,0 +1 @@
+require 'hatchet/tasks'
@@ -15,55 +15,97 @@
 # Fail fast and fail hard.
 set -eo pipefail

-# Standard Library.
+# 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 virtualenv hackery. This will be deprecated soon.
+# Prepend proper path for old-school virtualenv hackery.
+# This may not be neccessary.
 export PATH=:/usr/local/bin:$PATH

-# Paths.
-BIN_DIR=$(cd $(dirname $0); pwd) # absolute path
-ROOT_DIR=$(dirname $BIN_DIR)
+# Setup Path variables, for later use in the Buildpack.
+BIN_DIR=$(cd "$(dirname "$0")"; pwd) # absolute path
+ROOT_DIR=$(dirname "$BIN_DIR")
 BUILD_DIR=$1
 CACHE_DIR=$2
 ENV_DIR=$3

-# Python defaults
-DEFAULT_PYTHON_VERSION="python-3.6.2"
-DEFAULT_PYTHON_STACK="cedar-14"
-PYTHON_EXE="/app/.heroku/python/bin/python"
-PIP_VERSION="9.0.1"
+# Export Path variables, for use in sub-scripts.
+export BUILD_DIR CACHE_DIR ENV_DIR

-# Common Problem Warnings
-export WARNINGS_LOG=$(mktemp)
+# Set the Buildpack's internet target for downloading Python distributions.
+# The user can provide BUILDPACK_VENDOR_URL to specify a custom target.
+# Note: this is designed for non-Heroku use, as it does not use the user-provided
+# environment variable mechanism (the ENV_DIR).
+VENDOR_URL="https://lang-python.s3.amazonaws.com/$STACK"
+if [[ -n ${BUILDPACK_VENDOR_URL:-} ]]; then
+    VENDOR_URL="$BUILDPACK_VENDOR_URL"
+fi
+export VENDOR_URL
+
+# Which versions of Python are we using?
+# These variables are used to specify which versions of Python to install by default,
+# as well as prompt the user to upgrade if they are using an un–supported version.
+# Note: When 3.7 lands, I recommend switching to LATEST_36 and LATEST_37.
+DEFAULT_PYTHON_VERSION="python-3.6.6"
+LATEST_36="python-3.6.6"
+LATEST_37="python-3.7.0"
+LATEST_2="python-2.7.15"
+
+# Which stack is used (for binary downloading), if none is provided (e.g. outside of Heroku)?
+DEFAULT_PYTHON_STACK="cedar-14"
+# If pip doesn't match this version (the version we install), run the installer.
+PIP_UPDATE="9.0.2"
+
+export DEFAULT_PYTHON_VERSION DEFAULT_PYTHON_STACK PIP_UPDATE LATEST_2 LATEST_36 LATEST_37
+
+# 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

-# Setup vendored tools and pip-pop (pip-diff)
+# 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

-# Support Anvil Build_IDs
+# 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:
+# 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

-# Syntax sugar.
-source $BIN_DIR/utils
+# Import the utils script, which contains helper functions used throughout the buildpack.
+# shellcheck source=bin/utils
+source "$BIN_DIR/utils"

-# Import collection of warnings.
-source $BIN_DIR/warnings
+# Import the warnings script, which contains the `pip install` user warning mechanisms
+# (mentioned and explained above)
+# shellcheck source=bin/warnings
+source "$BIN_DIR/warnings"

-# we need to put a bunch of symlinks in there later
+# 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

-# Set up outputs under new context
+# 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="$BUILD_DIR/.profile.d/python.gunicorn.sh"
@@ -72,169 +114,270 @@ WEB_CONCURRENCY_PROFILE_PATH="$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_PATH

-# Prepend proper environment variables for Python use.
+# Python Environment Variables
+# Set Python-specific environment variables, for running Python within the buildpack.
+# Notes on each variable included.
+
+# PATH is relatively obvious, we need to be able to execute 'python'.
 export PATH=/app/.heroku/python/bin:/app/.heroku/vendor/bin:$PATH
+# Tell Python to not buffer it's stdin/stdout.
 export PYTHONUNBUFFERED=1
+# Set the locale to a well-known and expected standard.
 export LANG=en_US.UTF-8
+# `~/.heroku/vendor` is an place where the buildpack may stick pre-build binaries for known
+# C dependencies (e.g. libmemcached on cedar-14). This section configures Python (GCC, more specifically)
+# and pip to automatically include these paths when building binaries.
 export C_INCLUDE_PATH=/app/.heroku/vendor/include:/app/.heroku/python/include:$C_INCLUDE_PATH
 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"

-# Warn for lack of Procfile.
-if [[ ! -f Procfile ]]; then
-  puts-warn 'Warning: Your application is missing a Procfile. This file tells Heroku how to run your application.'
-  puts-warn 'Learn more: https://devcenter.heroku.com/articles/procfile'
-fi
+# The Cache
+# ---------

-# Prepare the cache.
-mkdir -p $CACHE_DIR
+# The workflow for the Python Buildpack's cache is as follows:
+#
+# - `~/.heroku/{known-paths}` are copied from the cache into the slug.
+# - The build is executed, modifying `~/.heroku/{known-paths}`.
+# - Once the build is complete, `~/.heroku/{known-paths}` is copied back into the cache.
+
+# Create the cache directory, if it doesn't exist.
+mkdir -p "$CACHE_DIR"

 # Restore old artifacts from the cache.
 mkdir -p .heroku

-cp -R $CACHE_DIR/.heroku/python .heroku/ &> /dev/null || true
-cp -R $CACHE_DIR/.heroku/python-stack .heroku/ &> /dev/null || true
-cp -R $CACHE_DIR/.heroku/python-version .heroku/ &> /dev/null || true
-cp -R $CACHE_DIR/.heroku/vendor .heroku/ &> /dev/null || true
-if [[ -d $CACHE_DIR/.heroku/src ]]; then
-  cp -R $CACHE_DIR/.heroku/src .heroku/ &> /dev/null || true
+# The Python installation.
+cp -R "$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

-# Experimental pre_compile hook.
-source $BIN_DIR/steps/hooks/pre_compile
+# 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.

-# Sticky runtimes.
-if [ -f $CACHE_DIR/.heroku/python-version ]; then
-  DEFAULT_PYTHON_VERSION=$(cat $CACHE_DIR/.heroku/python-version)
+# shellcheck source=bin/steps/hooks/pre_compile
+source "$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

-# Stack fallback for non-declared caches.
-if [ -f $CACHE_DIR/.heroku/python-stack ]; then
-  CACHED_PYTHON_STACK=$(cat $CACHE_DIR/.heroku/python-stack)
+# We didn't always record the stack version. This code is in place because of that.
+if [ -f "$CACHE_DIR/.heroku/python-stack" ]; then
+  CACHED_PYTHON_STACK=$(cat "$CACHE_DIR/.heroku/python-stack")
 else
  CACHED_PYTHON_STACK=$STACK
 fi

-# Pipenv Python version support.
-source $BIN_DIR/steps/pipenv-python-version
+export CACHED_PYTHON_STACK

-# If no runtime given, assume default version.
+# 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 $DEFAULT_PYTHON_VERSION > runtime.txt
+  echo "$DEFAULT_PYTHON_VERSION" > runtime.txt
 fi

-mkdir -p $(dirname $PROFILE_PATH)
+# Create the directory for .profile.d, if it doesn't exist.
+mkdir -p "$(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 $BUILD_DIR/.heroku/vendor /app/.heroku/vendor
+    ln -nsf "$BUILD_DIR/.heroku/python" /app/.heroku/python
+    ln -nsf "$BUILD_DIR/.heroku/vendor" /app/.heroku/vendor
    # Note: .heroku/src is copied in later.
 fi

-# Install Python.
-let start=$(nowms)
-source $BIN_DIR/steps/python
+# Download / Install Python, from pre-build binaries available on Amazon S3.
+# This step also bootstraps pip / setuptools.
+(( start=$(nowms) ))
+# shellcheck source=bin/steps/python
+source "$BIN_DIR/steps/python"
 mtime "python.install.time" "${start}"

-# Pipenv support.
-source $BIN_DIR/steps/pipenv
+# Install Pipenv dependencies, if a Pipfile was provided.
+# shellcheck source=bin/steps/pipenv
+source "$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

 # Fix egg-links.
-source $BIN_DIR/steps/eggpath-fix
+# Because we're installing things into a different path than we're running them (temp dir vs app dir),
+# We must re-write all of Python's eggpath links to target the proper directory.
+# shellcheck source=bin/steps/eggpath-fix
+source "$BIN_DIR/steps/eggpath-fix"

 # 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.
-source $BIN_DIR/steps/cryptography
-
-# Support for Geo libraries.
-sub-env $BIN_DIR/steps/geo-libs
+# Support for Geo libraries. This is deprecated functionality, only functional on cedar-14.
+# It is undocumented.
+# shellcheck source=bin/steps/geo-libs
+sub_env "$BIN_DIR/steps/geo-libs"

 # GDAL support.
-source $BIN_DIR/steps/gdal
+# This is part of the Geo support.
+# shellcheck source=bin/steps/gdal
+source "$BIN_DIR/steps/gdal"

-# Uninstall removed dependencies with Pip.
-let start=$(nowms)
-source $BIN_DIR/steps/pip-uninstall
-mtime "pip.uninstall.time" "${start}"
+# 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}"

-# Install dependencies with Pip (where the magic happens).
-let start=$(nowms)
-source $BIN_DIR/steps/pip-install
+# pip install
+# -----------
+
+# Install dependencies with pip (where the magic happens).
+(( start=$(nowms) ))
+# shellcheck source=bin/steps/pip-install
+source "$BIN_DIR/steps/pip-install"
 mtime "pip.install.time" "${start}"

 # Support for NLTK corpora.
-let start=$(nowms)
-sub-env $BIN_DIR/steps/nltk
+# Note: this may only work on Python 2.7. I don't think many customers use this functionality,
+# and it should probably be undocumented.
+# (there's an import error on 3.6 that should hopefully be fixed upstream at some point)
+(( start=$(nowms) ))
+sub_env "$BIN_DIR/steps/nltk"
 mtime "nltk.download.time" "${start}"

-# Support for pip install -e.
+# 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 $BUILD_DIR/.heroku/src
+  rm -fr "$BUILD_DIR/.heroku/src"
+  deep-cp /app/.heroku/src "$BUILD_DIR/.heroku/src"
 fi


 # Django collectstatic support.
-let start=$(nowms)
-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}"

-# Create .profile script for application runtime environment variables.
-set-env PATH '$HOME/.heroku/python/bin:$PATH'
-set-env PYTHONUNBUFFERED true
-set-env PYTHONHOME /app/.heroku/python
-set-env LIBRARY_PATH '/app/.heroku/vendor/lib:/app/.heroku/python/lib:$LIBRARY_PATH'
-set-env LD_LIBRARY_PATH '/app/.heroku/vendor/lib:/app/.heroku/python/lib:$LD_LIBRARY_PATH'
-set-default-env LANG en_US.UTF-8
-set-default-env PYTHONHASHSEED random
-set-default-env PYTHONPATH /app/
+
+# Progamatically create .profile.d script for application runtime environment variables.
+
+# Set the PATH to include Python / pip / pipenv / etc.
+set_env PATH "\$HOME/.heroku/python/bin:\$PATH"
+# Tell Python to run in unbuffered mode.
+set_env PYTHONUNBUFFERED true
+# Tell Python where it lives.
+set_env PYTHONHOME "\$HOME/.heroku/python"
+# Set variables for C libraries.
+set_env LIBRARY_PATH "\$HOME/.heroku/vendor/lib:\$HOME/.heroku/python/lib:\$LIBRARY_PATH"
+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"
+
+# Python expects to be in /app, if at runtime, it is not, set
+# 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 $GUNICORN_PROFILE_PATH
+cp "$ROOT_DIR/vendor/WEB_CONCURRENCY.sh" "$WEB_CONCURRENCY_PROFILE_PATH"
+cp "$ROOT_DIR/vendor/python.gunicorn.sh" "$GUNICORN_PROFILE_PATH"

-
-# Experimental post_compile hook.
-source $BIN_DIR/steps/hooks/post_compile
+# Experimental post_compile hook. Don't remove this.
+# shellcheck source=bin/steps/hooks/post_compile
+source "$BIN_DIR/steps/hooks/post_compile"

 # Fix egg-links, again.
-source $BIN_DIR/steps/eggpath-fix2
+# shellcheck source=bin/steps/eggpath-fix2
+source "$BIN_DIR/steps/eggpath-fix2"

-# Store new artifacts in cache.
+# Store new artifacts in the cache.
+rm -rf "$CACHE_DIR/.heroku/python"
+rm -rf "$CACHE_DIR/.heroku/python-version"
+rm -rf "$CACHE_DIR/.heroku/python-stack"
+rm -rf "$CACHE_DIR/.heroku/vendor"
+rm -rf "$CACHE_DIR/.heroku/src"

-rm -rf $CACHE_DIR/.heroku/python
-rm -rf $CACHE_DIR/.heroku/python-version
-rm -rf $CACHE_DIR/.heroku/python-stack
-rm -rf $CACHE_DIR/.heroku/vendor
-rm -rf $CACHE_DIR/.heroku/src
-
-mkdir -p $CACHE_DIR/.heroku
-cp -R .heroku/python $CACHE_DIR/.heroku/
-cp -R .heroku/python-version $CACHE_DIR/.heroku/
-cp -R .heroku/python-stack $CACHE_DIR/.heroku/ &> /dev/null || true
-cp -R .heroku/vendor $CACHE_DIR/.heroku/ &> /dev/null || true
+mkdir -p "$CACHE_DIR/.heroku"
+cp -R .heroku/python "$CACHE_DIR/.heroku/"
+cp -R .heroku/python-version "$CACHE_DIR/.heroku/"
+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 $CACHE_DIR/.heroku/ &> /dev/null || true
+  cp -R .heroku/src "$CACHE_DIR/.heroku/" &> /dev/null || true
 fi

 # Measure the size of the Python installation.
+# shellcheck disable=SC2119
 mmeasure 'python.size' "$(measure-size)"
@@ -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 ] && [ ! -f $BUILD_DIR/Pipfile ]; then
+if [ ! -f "$BUILD_DIR/requirements.txt" ] && [ ! -f "$BUILD_DIR/setup.py" ] && [ ! -f "$BUILD_DIR/Pipfile" ]; then
  exit 1
 fi

@@ -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
@@ -10,7 +10,8 @@
 #   - $DISABLE_COLLECTSTATIC: disables this functionality.
 #   - $DEBUG_COLLECTSTATIC: upon failure, print out environment variables.

-source $BIN_DIR/utils
+# shellcheck source=bin/utils
+source "$BIN_DIR/utils"

 # Location of 'manage.py', if it exists.
 MANAGE_FILE=$(find . -maxdepth 3 -type f -name 'manage.py' -printf '%d\t%P\n' | sort -nk1 | cut -f2 | head -1)
@@ -29,13 +30,35 @@ if [ ! "$DISABLE_COLLECTSTATIC" ] && [ -f "$MANAGE_FILE" ] && [ "$DJANGO_INSTALL
    puts-step "$ python $MANAGE_FILE collectstatic --noinput"

    # Run collectstatic, cleanup some of the noisy output.
-    python $MANAGE_FILE collectstatic --noinput --traceback 2>&1 | sed '/^Post-processed/d;/^Copying/d;/^$/d' | indent
+    PYTHONPATH=${PYTHONPATH:-.}
+    export PYTHONPATH
+
+    # Create a temporary file for collecting the collectstaic logs.
+    COLLECTSTATIC_LOG=$(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.
-    [ $COLLECTSTATIC_STATUS -ne 0 ] && {
+    [ "$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 $MANAGE_FILE collectstatic --noinput'."
@@ -1,31 +0,0 @@
-#!/usr/bin/env bash
-
-# This script serves as the Cryptography build step of the
-# [**Python Buildpack**](https://github.com/heroku/heroku-buildpack-python)
-# compiler.
-#
-# A [buildpack](https://devcenter.heroku.com/articles/buildpacks) is an
-# adapter between a Python application and Heroku's runtime.
-#
-# This script is invoked by [`bin/compile`](/).
-
-# The location of the pre-compiled libffi binary.
-VENDORED_LIBFFI="https://lang-python.s3.amazonaws.com/$STACK/libraries/vendor/libffi.tar.gz"
-
-PKG_CONFIG_PATH="/app/.heroku/vendor/lib/pkgconfig:$PKG_CONFIG_PATH"
-
-# Syntax sugar.
-source $BIN_DIR/utils
-
-# If a package using cffi exists within requirements, use vendored libffi.
-if (pip-grep -s requirements.txt argon2-cffi bcrypt cffi cryptography django[argon2] Django[argon2] django[bcrypt] Django[bcrypt] PyNaCl pyOpenSSL PyOpenSSL requests[security] misaka &> /dev/null) then
-
-  if [ ! -d ".heroku/vendor/lib/libffi-3.1" ]; then
-    echo "-----> Noticed cffi. Bootstrapping libffi."
-    mkdir -p .heroku/vendor
-    # Download and extract libffi into target vendor directory.
-    curl $VENDORED_LIBFFI -s | tar zxv -C .heroku/vendor &> /dev/null
-  fi
-
-  export LIBFFI=$(pwd)/vendor
-fi
@@ -1,3 +1,5 @@
+#!/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
@@ -1,3 +1,4 @@
+#!/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
@@ -10,12 +10,13 @@
 # This script is invoked by [`bin/compile`](/).

 # The location of the pre-compiled cryptography binary.
-VENDORED_GDAL="https://lang-python.s3.amazonaws.com/$STACK/libraries/vendor/gdal.tar.gz"
+VENDORED_GDAL="${VENDOR_URL}/libraries/vendor/gdal.tar.gz"

 PKG_CONFIG_PATH="/app/.heroku/vendor/lib/pkgconfig:$PKG_CONFIG_PATH"

 # Syntax sugar.
-source $BIN_DIR/utils
+# shellcheck source=bin/utils
+source "$BIN_DIR/utils"

 # If GDAL exists within requirements, use vendored gdal.
 if (pip-grep -s requirements.txt GDAL gdal pygdal &> /dev/null) then
@@ -24,9 +25,10 @@ if (pip-grep -s requirements.txt GDAL gdal pygdal &> /dev/null) then
    echo "-----> Noticed GDAL. Bootstrapping gdal."
    mkdir -p .heroku/vendor
    # Download and extract cryptography into target vendor directory.
-    curl $VENDORED_GDAL -s | tar zxv -C .heroku/vendor &> /dev/null
+    curl "$VENDORED_GDAL" -s | tar zxv -C .heroku/vendor &> /dev/null
  fi

-  export GDAL=$(pwd)/vendor
+  GDAL=$(pwd)/vendor
+  export GDAL
 fi

@@ -10,14 +10,15 @@
 # This script is invoked by [`bin/compile`](/).

 # The location of the pre-compiled cryptography binary.
-VENDORED_GDAL="https://lang-python.s3.amazonaws.com/$STACK/libraries/vendor/gdal.tar.gz"
-VENDORED_GEOS="https://lang-python.s3.amazonaws.com/$STACK/libraries/vendor/geos.tar.gz"
-VENDORED_PROJ="https://lang-python.s3.amazonaws.com/$STACK/libraries/vendor/proj.tar.gz"
+VENDORED_GDAL="${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.
-source $BIN_DIR/utils
+# shellcheck source=bin/utils
+source "$BIN_DIR/utils"

 # If GDAL exists within requirements, use vendored gdal.
 if [[ "$BUILD_WITH_GEO_LIBRARIES" ]]; then
@@ -26,11 +27,23 @@ if [[ "$BUILD_WITH_GEO_LIBRARIES" ]]; 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 $VENDORED_PROJ -s | tar zxv -C .heroku/vendor &> /dev/null
+    curl "$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
+
+    # Copy libjasper from build image to slug.
+    if [[ "$STACK" == "heroku-16" ]]; then
+      cp /usr/lib/x86_64-linux-gnu/libjasper.so* ".heroku/vendor/lib/."
+    fi
+
  fi

-  export GDAL=$(pwd)/vendor
+  GDAL=$(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
-
@@ -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
@@ -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
@@ -1,4 +1,9 @@
+#!/usr/bin/env bash
+
 # Install Mercurial if it appears to be required.
-if (grep -Fiq "hg+" requirements.txt) then
-    /app/.heroku/python/bin/pip install  mercurial | cleanup | indent
+if [[ -f "requirements.txt" ]]; then
+	if (grep -Fiq "hg+" requirements.txt) then
+		/app/.heroku/python/bin/pip install  mercurial | cleanup | indent
+	fi
 fi
+
@@ -10,21 +10,25 @@
 # This script is invoked by [`bin/compile`](/).

 # Syntax sugar.
-source $BIN_DIR/utils
+# shellcheck source=bin/utils
+source "$BIN_DIR/utils"

 # Check that nltk was installed by pip, otherwise obviously not needed
-python -m nltk.downloader -h >/dev/null 2>&1
-if [ $? -eq 0 ]; then
-    puts-step "Downloading NLTK corpora..."
+if sp-grep -s nltk; then
+    puts-step "Downloading NLTK corpora…"
+
    nltk_packages_definition="$BUILD_DIR/nltk.txt"
+
    if [ -f "$nltk_packages_definition" ]; then
-        nltk_packages=$(tr "\n" " " < "$nltk_packages_definition")
-        puts-step "Downloading NLTK packages: $nltk_packages"
-        python -m nltk.downloader -d $BUILD_DIR/.heroku/python/nltk_data $nltk_packages  | indent
-        set-env NLTK_DATA "/app/.heroku/python/nltk_data"
+
+        readarray -t nltk_packages < "$nltk_packages_definition"
+        puts-step "Downloading NLTK packages: ${nltk_packages[*]}"
+
+        python -m nltk.downloader -d "$BUILD_DIR/.heroku/python/nltk_data" "${nltk_packages[@]}" | indent
+        set_env NLTK_DATA "/app/.heroku/python/nltk_data"
+
    else
        puts-warn "'nltk.txt' not found, not downloading any corpora"
        puts-warn "Learn more: https://devcenter.heroku.com/articles/python-nltk"
    fi
 fi
-
@@ -1,23 +1,66 @@
+#!/usr/bin/env bash
+
+# shellcheck source=bin/utils
+source "$BIN_DIR/utils"
+
 if [ ! "$SKIP_PIP_INSTALL" ]; then

    # Install dependencies with Pip.
    puts-step "Installing requirements with pip"

+    # 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 +e
-    /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 $WARNINGS_LOG | cleanup | indent
+
+    # Set SLUGIFY_USES_TEXT_UNIDECODE, required for Airflow versions >=1.10
+    if [[ -r "$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
+
+    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
+
+
+    /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
-fi
+
+    # 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 "$1/requirements-test.txt" --exists-action=w --src=./.heroku/src --disable-pip-version-check --no-cache-dir 2>&1 | cleanup | indent
+        fi
+    fi
+fi
@@ -1,18 +1,28 @@
+#!/usr/bin/env bash
+
 set +e
 # Install dependencies with Pip.
+# shellcheck source=bin/utils
+source "$BIN_DIR/utils"

-if [[ -f .heroku/python/requirements-declared.txt ]]; then
+if [ ! "$SKIP_PIP_INSTALL" ]; then

-  cp .heroku/python/requirements-declared.txt requirements-declared.txt
+  if [[ -f .heroku/python/requirements-declared.txt ]]; then

-  pip-diff --stale requirements-declared.txt requirements.txt --exclude setuptools pip wheel > .heroku/python/requirements-stale.txt
+    cp .heroku/python/requirements-declared.txt requirements-declared.txt

-  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 | cleanup | indent
+    if ! pip-diff --stale requirements-declared.txt requirements.txt --exclude setuptools pip wheel > .heroku/python/requirements-stale.txt; then
+      mount "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

+fi
 set -e
@@ -1,19 +1,86 @@
-# Pipenv support (Generate requriements.txt with pipenv).
-if [[ -f Pipfile ]]; then
-    if [[ ! -f requirements.txt ]]; then
-        puts-step "Installing requirements with latest pipenv..."
+#!/usr/bin/env bash

-        # Install pipenv.
-        /app/.heroku/python/bin/pip install pipenv --upgrade &> /dev/null
+# export CLINT_FORCE_COLOR=1
+# export PIPENV_FORCE_COLOR=1
+# shellcheck source=bin/utils
+source "$BIN_DIR/utils"
+set -e

-        # Install the dependencies.
-        /app/.heroku/python/bin/pipenv install --system 2>&1 | indent
+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 requriements.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

-        # Pip freeze, for compatibility.
-        /app/.heroku/python/bin/pip freeze > requirements.txt
+        # 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 dependencies.
+        if [[ ! -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 $PIPENV_VERSION…"
+            /app/.heroku/python/bin/pipenv install --system --deploy 2>&1 | indent
+        fi
+
+        # Install the test dependencies, for CI.
+        if [ "$INSTALL_TEST" ]; then
+            puts-step "Installing test dependencies…"
+            /app/.heroku/python/bin/pipenv install --dev --system --deploy 2>&1 | cleanup | indent
+        fi
    fi
-fi
+else
+    export SKIP_PIP_INSTALL=1
+    pipenv-to-pip Pipfile.lock > requirements.txt
+fi
@@ -1,22 +1,35 @@
+#!/usr/bin/env bash
+
 # Detect Python-version with Pipenv.

-if [[ -f $BUILD_DIR/Pipfile.lock ]]; then
+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."
+            puts-warn "No 'Pipfile.lock' found! We recommend you commit this into your repository."
        fi
        if [[ -f $BUILD_DIR/Pipfile.lock ]]; then
            set +e
-            PYTHON=$(cat $BUILD_DIR/Pipfile.lock | jq '._meta.requires.python_version' -r)
+            PYTHON=$(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" = 2.7 ]; then
-                echo "python-2.7.13" > $BUILD_DIR/runtime.txt
-            fi
-            if [ "$PYTHON" = 3.6 ]; then
-                echo "python-3.6.0" > $BUILD_DIR/runtime.txt
+            if [[ "$PYTHON" == "null" ]]; then
+                PYTHON=$(jq -r '._meta.requires.python_version' "$BUILD_DIR/Pipfile.lock")
+                if [ "$PYTHON" = 2.7 ]; then
+                    echo "$LATEST_2" > "$BUILD_DIR/runtime.txt"
+                fi
+                if [ "$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
@@ -9,12 +9,17 @@
 #
 # This script is invoked by [`bin/compile`](/).

+if [[ "$STACK" != "cedar-14" ]]; then
+    # libmemcached is pre-installed in the stack image so there is no need to vendor it.
+    return 0
+fi
+
 # The location of the pre-compiled libmemcached binary.
-VENDORED_MEMCACHED="https://lang-python.s3.amazonaws.com/$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"

 # If pylibmc exists within requirements, use vendored libmemcached.
 if (pip-grep -s requirements.txt pylibmc &> /dev/null) then
@@ -23,8 +28,9 @@ if (pip-grep -s requirements.txt pylibmc &> /dev/null) then
    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
  fi

-  export LIBMEMCACHED=$(pwd)/vendor
+  LIBMEMCACHED=$(pwd)/vendor
+  export LIBMEMCACHED
 fi
@@ -1,10 +1,64 @@
+#!/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"
+
+if [[ $PYTHON_VERSION =~ ^python-2 ]]; then
+  if [[ "$PYTHON_VERSION" != "$LATEST_2" ]]; then
+    puts-warn "The latest version of Python 2 is $LATEST_2 (you are using $PYTHON_VERSION, which is unsupported)."
+    puts-warn "We recommend upgrading by specifying the latest version ($LATEST_2)."
+    echo "       Learn More: https://devcenter.heroku.com/articles/python-runtimes"
+  else
+    echo "       Using supported version of Python 2 ($PYTHON_VERSION)"
+  fi
+else
+  if [[ $PYTHON_VERSION =~ ^python-3 ]]; then
+    if [[ $PYTHON_VERSION =~ ^python-3.7 ]]; then
+      if [[ "$PYTHON_VERSION" != "$LATEST_37" ]]; then
+      puts-warn "The latest version of Python 3.7 is $LATEST_37 (you are using $PYTHON_VERSION, which is unsupported)."
+      puts-warn "We recommend upgrading by specifying the latest version ($LATEST_37)."
+      echo "       Learn More: https://devcenter.heroku.com/articles/python-runtimes"
+      else
+        echo "       Using supported version of Python 3.7 ($PYTHON_VERSION)"
+      fi
+    else
+      if [[ $PYTHON_VERSION =~ ^python-3.6 ]]; then
+        if [[ "$PYTHON_VERSION" != "$LATEST_36" ]]; then
+          puts-warn "The latest version of Python 3.6 is $LATEST_36 (you are using $PYTHON_VERSION, which is unsupported)."
+          puts-warn "We recommend upgrading by specifying the latest version ($LATEST_36)."
+          echo "       Learn More: https://devcenter.heroku.com/articles/python-runtimes"
+        else
+          echo "       Using supported version of Python 3.6 ($PYTHON_VERSION)"
+        fi
+      else
+        puts-warn "Heroku supports runtime versions $LATEST_37, $LATEST_36 and $LATEST_2." 
+        puts-warn "You are using $PYTHON_VERSION, which is unsupported."
+        puts-warn "We recommend upgrading by specifying the default supported version ($LATEST_36)."
+        echo "       Learn More: https://devcenter.heroku.com/articles/python-runtimes"
+      fi
+    fi
+  fi
+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
      puts-step "Found $(cat .heroku/python-version), removing"
      rm -fr .heroku/python
  else
@@ -12,11 +66,6 @@ if [ -f .heroku/python-version ]; then
  fi
 fi

-if [ ! $STACK = $CACHED_PYTHON_STACK ]; then
-    rm -fr .heroku/python .heroku/python-stack .heroku/vendor
-    unset SKIP_INSTALL
-fi
-

 if [ ! "$SKIP_INSTALL" ]; then
    puts-step "Installing $PYTHON_VERSION"
@@ -24,37 +73,34 @@ if [ ! "$SKIP_INSTALL" ]; then
    # Prepare destination directory.
    mkdir -p .heroku/python

-    curl https://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

  # Record for future reference.
-  echo $PYTHON_VERSION > .heroku/python-version
-  echo $STACK > .heroku/python-stack
+  echo "$PYTHON_VERSION" > .heroku/python-version
+  echo "$STACK" > .heroku/python-stack
  FRESH_PYTHON=true

  hash -r
 fi

-# If Pip isn't up to date:
-if [ "$FRESH_PYTHON" ] || [[ ! $(pip --version) == *$PIP_VERSION* ]]; then
-  WORKING_DIR=$(pwd)

-  TMPTARDIR=$(mktemp -d)
-  trap "rm -rf $TMPTARDIR" RETURN
+# If Pip isn't up to date:
+if [ "$FRESH_PYTHON" ] || [[ ! $(pip --version) == *$PIP_UPDATE* ]]; then

  puts-step "Installing pip"

  # Remove old installations.
-  rm -fr /app/.heroku/python/lib/python2.7/site-packages/pip-*
-  rm -fr /app/.heroku/python/lib/python2.7/site-packages/setuptools-*
+  rm -fr /app/.heroku/python/lib/python*/site-packages/pip-*
+  rm -fr /app/.heroku/python/lib/python*/site-packages/setuptools-*

-  /app/.heroku/python/bin/python $ROOT_DIR/vendor/get-pip.py &> /dev/null
+  /app/.heroku/python/bin/python "$ROOT_DIR/vendor/get-pip.py" pip=="$PIP_UPDATE" &> /dev/null
+  /app/.heroku/python/bin/pip install "$ROOT_DIR/vendor/setuptools-39.0.1-py2.py3-none-any.whl" &> /dev/null

 fi

@@ -0,0 +1,87 @@
+#!/usr/bin/env bash
+
+# shellcheck source=bin/utils
+source "$BIN_DIR/utils"
+
+sqlite3_version() {
+  SQLITE3_VERSION=${SQLITE3_VERSION:-$(dpkg -s libsqlite3-0 | grep Version | sed 's/Version: //')}
+
+  export SQLITE3_VERSION
+}
+
+sqlite3_install() {
+  HEROKU_PYTHON_DIR="$1"
+  SQLITE3_VERSION="$2"
+  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_VERSION" sqlite3="$SQLITE3_VERSION" > /dev/null 2>&1
+  else
+    apt-get $APT_OPTIONS -y -d --reinstall install libsqlite3-dev="$SQLITE3_VERSION"
+  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() {
+  sqlite3_version
+  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 "$SQLITE3_VERSION_FILE")
+  fi
+
+  # python version check
+  if python_sqlite3_check "$PYTHON_VERSION"; then
+    # only install if the sqlite3 version has changed
+    if [ "$INSTALLED_SQLITE3_VERSION" != "$SQLITE3_VERSION" ]; then
+      puts-step "Installing SQLite3"
+      sqlite3_install "$BUILD_DIR/.heroku/python" "$SQLITE3_VERSION"
+
+      # save version installed
+      mkdir -p "$CACHE_DIR/.heroku/"
+      echo "$SQLITE3_VERSION" > "$CACHE_DIR/.heroku/python-sqlite3-version"
+    fi
+  fi
+}
@@ -1,11 +1,13 @@
 #!/usr/bin/env bash

 # Syntax sugar.
-BIN_DIR=$(cd $(dirname $0); pwd) # absolute path
-source $BIN_DIR/utils
+BIN_DIR=$(cd "$(dirname "$0")" || return; pwd) # absolute path

-DISABLE_COLLECTSTATIC=1 "$(dirname ${0:-})/compile" "$1" "$2" "$3"
+# shellcheck source=bin/utils
+source "$BIN_DIR/utils"

-if [[ -f "$1/requirements-test.txt" ]]; then
-    /app/.heroku/python/bin/pip install -r "$1/requirements-test.txt" --exists-action=w --src=./.heroku/src --disable-pip-version-check --no-cache-dir 2>&1 | cleanup | indent
-fi
+# Locale support for Pipenv.
+export LC_ALL=C.UTF-8
+export LANG=C.UTF-8
+
+DISABLE_COLLECTSTATIC=1 INSTALL_TEST=1 "$(dirname "${0:-}")/compile" "$1" "$2" "$3"
@@ -1,13 +1,15 @@
 #!/usr/bin/env bash
 shopt -s extglob
+shopt -s nullglob

 # The standard library.
 if [[ ! -f  /tmp/stdlib.sh ]]; then
-  curl --retry 3 -s https://lang-common.s3.amazonaws.com/buildpack-stdlib/v2/stdlib.sh > /tmp/stdlib.sh
+  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 [ $(uname) == Darwin ]; then
+if [ "$(uname)" == Darwin ]; then
    sed() { command sed -l "$@"; }
 else
    sed() { command sed -u "$@"; }
@@ -26,12 +28,12 @@ cleanup() {

 # Buildpack Steps.
 puts-step() {
-  echo "-----> $@"
+  echo "-----> $*"
 }

 # Buildpack Warnings.
 puts-warn() {
-  echo " !     $@"
+  echo " !     $*"
 }

 # Does some serious copying.
@@ -51,31 +53,46 @@ deep-cp() {
 }


-sub-env() {
-
-  WHITELIST=${2:-''}
-  BLACKLIST=${3:-'^(GIT_DIR|STACK|PYTHONHOME|LD_LIBRARY_PATH|LIBRARY_PATH|PATH)$'}
-
-  # Python-specific variables.
-  export PYHONHOME=$BUILD_DIR/.heroku/python
-  export PYTHONPATH=$BUILD_DIR/
-
-  (
-    if [ -d "$ENV_DIR" ]; then
-      for e in $(ls $ENV_DIR); do
-        echo "$e" | grep -E "$WHITELIST" | grep -qvE "$BLACKLIST" &&
-        export "$e=$(cat $ENV_DIR/$e)"
-        :
-      done
-    fi
-
-    $1
-
-  )
-}
-
 # Measure the size of the Python installation.
 measure-size() {
-  echo "$((du -s .heroku/python 2>/dev/null || echo 0) | awk '{print $1}')"
+  echo "$(du -s .heroku/python 2>/dev/null || echo 0) | awk '{print $1}')"
 }

+# Python version operator >
+version_gt() {
+  test "$(printf '%s\n' "$@" | sort -V | head -n 1)" != "$1";
+}
+
+# Python verison operator >=
+version_gte() {
+  if [ "$1" == "$2" ]; then
+    return 0
+  fi
+
+  version_gt "$1" "$2"
+}
+
+# Check if Python 2
+python2_check() {
+  VERSION="$1"
+
+  version_gte "$VERSION" "python-2.7.0" && version_gt "python-3.0.0" "$VERSION"
+}
+
+# Check if Python 3
+python3_check() {
+  VERSION="$1"
+
+  version_gte "$VERSION" "python-3.0.0" && version_gt "python-4.0.0" "$VERSION"
+}
+
+# Check if Python version needs to install SQLite3
+python_sqlite3_check() {
+  VERSION="$1"
+  MIN_PYTHON_3="python-3.6.6"
+  MIN_PYTHON_2="python-2.7.15"
+
+  ( python2_check "$VERSION" && version_gte "$VERSION" "$MIN_PYTHON_2" ) \
+    || ( python3_check "$VERSION" && version_gte "$VERSION" "$MIN_PYTHON_3" ) \
+    || ( version_gte "$VERSION" "3.7.0" )
+}
@@ -1,3 +1,4 @@
+#!/usr/bin/env bash
 shopt -s extglob

 old-platform() {
@@ -0,0 +1,13 @@
+[buildpack]
+name = "Python"
+
+  [publish.Ignore]
+  files = [
+    "test/",
+    ".gitignore",
+    ".dockerignore",
+    ".github/",
+    "Dockerfile",
+    "Pipfile",
+    "Pipfile.lock"
+  ]
@@ -3,7 +3,7 @@

 OUT_PREFIX=$1

-echo "Building SQLite..."
+echo "Building SQLite…"


 SOURCE_TARBALL='https://www.sqlite.org/sqlite-autoconf-3070900.tar.gz'
@@ -8,16 +8,17 @@ export PATH="/app/.heroku/python/bin/:$PATH"
 hash -r


-echo "Building gdal..."
+echo "Building gdal…"

-SOURCE_TARBALL='http://download.osgeo.org/gdal/1.11.1/gdal-1.11.1.tar.gz'
+VERSION="2.2.1"
+SOURCE_TARBALL="http://download.osgeo.org/gdal/${VERSION}/gdal-${VERSION}.tar.gz"

 curl -L $SOURCE_TARBALL | tar zx

-cd gdal-1.11.1
+pushd "gdal-${VERSION}"
 ./configure --prefix=$OUT_PREFIX --enable-static=no  &&
 make
 make install

 # Cleanup
-cd ..
+popd
@@ -8,16 +8,18 @@ export PATH="/app/.heroku/python/bin/:$PATH"
 hash -r


-echo "Building geos..."
+echo "Building geos…"

-SOURCE_TARBALL='http://download.osgeo.org/geos/geos-3.4.3.tar.bz2'
+VERSION=3.6.2
+
+SOURCE_TARBALL="http://download.osgeo.org/geos/geos-${VERSION}.tar.bz2"

 curl -L $SOURCE_TARBALL | tar xj

-cd geos-3.4.3
+pushd "geos-${VERSION}"
 ./configure --prefix=$OUT_PREFIX --enable-static=no &&
 make
 make install

 # Cleanup
-cd ..
+popd
@@ -13,7 +13,7 @@ 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'

@@ -20,7 +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
@@ -33,7 +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 ${dep_dirname}
@@ -8,16 +8,17 @@ export PATH="/app/.heroku/python/bin/:$PATH"
 hash -r


-echo "Building gdal..."
+echo "Building gdal…"

-SOURCE_TARBALL='http://download.osgeo.org/proj/proj-4.8.0.tar.gz'
+VERSION=4.9.3
+SOURCE_TARBALL="http://download.osgeo.org/proj/proj-${VERSION}.tar.gz"

 curl -L $SOURCE_TARBALL | tar zx

-cd proj-4.8.0
-./configure --prefix=$OUT_PREFIX --enable-static=no &&
+pushd "proj-${VERSION}"
+./configure --prefix=$OUT_PREFIX --enable-static=no
 make
 make install

 # Cleanup
-cd ..
+popd
@@ -6,7 +6,7 @@

 OUT_PREFIX=$1

-echo "Building PyPy..."
+echo "Building PyPy…"
 SOURCE_TARBALL='https://bitbucket.org/pypy/pypy/downloads/pypy2-v5.3.1-linux64.tar.bz2'
 curl -L $SOURCE_TARBALL | tar jx
 cp -R pypy2-v5.3.1-linux64/* $OUT_PREFIX
@@ -6,7 +6,7 @@

 OUT_PREFIX=$1

-echo "Building PyPy..."
+echo "Building PyPy…"
 SOURCE_TARBALL='https://bitbucket.org/pypy/pypy/downloads/pypy2-v5.6.0-linux64.tar.bz2'
 curl -L $SOURCE_TARBALL | tar jx
 cp -R pypy2-v5.6.0-linux64/* $OUT_PREFIX
@@ -6,7 +6,7 @@

 OUT_PREFIX=$1

-echo "Building PyPy..."
+echo "Building PyPy…"
 SOURCE_TARBALL='https://bitbucket.org/pypy/pypy/downloads/pypy2-v5.7.0-linux64.tar.bz2'
 curl -L $SOURCE_TARBALL | tar jx
 cp -R pypy2-v5.7.0-linux64/* $OUT_PREFIX
@@ -6,7 +6,7 @@

 OUT_PREFIX=$1

-echo "Building PyPy..."
+echo "Building PyPy…"
 SOURCE_TARBALL='https://bitbucket.org/pypy/pypy/downloads/pypy2-v5.7.1-linux64.tar.bz2'
 curl -L $SOURCE_TARBALL | tar jx
 cp -R pypy2-v5.7.1-linux64/* $OUT_PREFIX
@@ -0,0 +1,12 @@
+#!/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/pypy2-v5.8.0-linux64.tar.bz2'
+curl -L $SOURCE_TARBALL | tar jx
+cp -R pypy2-v5.8.0-linux64/* $OUT_PREFIX
+
+ln $OUT_PREFIX/bin/pypy $OUT_PREFIX/bin/python
@@ -6,7 +6,7 @@

 OUT_PREFIX=$1

-echo "Building PyPy..."
+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
@@ -6,7 +6,7 @@

 OUT_PREFIX=$1

-echo "Building PyPy..."
+echo "Building PyPy…"
 SOURCE_TARBALL='https://bitbucket.org/pypy/pypy/downloads/pypy3.3-v5.5.0-alpha-linux64.tar.bz2'
 curl -L $SOURCE_TARBALL | tar jx
 cp -R pypy3-v5.5.0-linux64/* $OUT_PREFIX
@@ -4,7 +4,7 @@

 OUT_PREFIX=$1

-echo "Building PyPy..."
+echo "Building PyPy…"
 SOURCE_TARBALL='https://bitbucket.org/pypy/pypy/downloads/pypy3-v5.7.1-linux64.tar.bz2'
 curl -L $SOURCE_TARBALL | tar jx
 cp -R pypy3-v5.7.1-linux64/* $OUT_PREFIX
@@ -4,7 +4,7 @@

 OUT_PREFIX=$1

-echo "Building PyPy..."
+echo "Building PyPy…"
 SOURCE_TARBALL='https://bitbucket.org/pypy/pypy/downloads/pypy3-v5.8.0-linux64.tar.bz2'
 curl -L $SOURCE_TARBALL | tar jx
 cp -R pypy3-v5.8.0-linux64/* $OUT_PREFIX
@@ -4,7 +4,7 @@

 OUT_PREFIX=$1

-echo "Building Python..."
+echo "Building Python…"
 SOURCE_TARBALL='https://python.org/ftp/python/2.7.10/Python-2.7.10.tgz'
 curl -L $SOURCE_TARBALL | tar xz
 mv Python-2.7.10 src
@@ -4,7 +4,7 @@

 OUT_PREFIX=$1

-echo "Building Python..."
+echo "Building Python…"
 SOURCE_TARBALL='https://python.org/ftp/python/2.7.11/Python-2.7.11.tgz'
 curl -L $SOURCE_TARBALL | tar xz
 mv Python-2.7.11 src
@@ -4,7 +4,7 @@

 OUT_PREFIX=$1

-echo "Building Python..."
+echo "Building Python…"
 SOURCE_TARBALL='https://python.org/ftp/python/2.7.12/Python-2.7.12.tgz'
 curl -L $SOURCE_TARBALL | tar xz
 mv Python-2.7.12 src
@@ -4,7 +4,7 @@

 OUT_PREFIX=$1

-echo "Building Python..."
+echo "Building Python…"
 SOURCE_TARBALL='https://python.org/ftp/python/2.7.13/Python-2.7.13.tgz'
 curl -L $SOURCE_TARBALL | tar xz
 mv Python-2.7.13 src
@@ -13,3 +13,7 @@ cd src
 ./configure --prefix=$OUT_PREFIX  --enable-unicode=ucs4 --with-ensurepip=no
 make
 make install
+
+# Remove unneeded test directories, similar to the official Docker Python images:
+# https://github.com/docker-library/python
+find "${OUT_PREFIX}" \( -type d -a \( -name test -o -name tests \) \) -exec rm -rf '{}' +
@@ -0,0 +1,19 @@
+#!/usr/bin/env bash
+# Build Path: /app/.heroku/python/
+# Build Deps: libraries/sqlite
+
+OUT_PREFIX=$1
+
+echo "Building Python…"
+SOURCE_TARBALL='https://python.org/ftp/python/2.7.14/Python-2.7.14.tgz'
+curl -L $SOURCE_TARBALL | tar xz
+mv Python-2.7.14 src
+cd src
+
+./configure --prefix=$OUT_PREFIX  --enable-unicode=ucs4 --with-ensurepip=no
+make
+make install
+
+# Remove unneeded test directories, similar to the official Docker Python images:
+# https://github.com/docker-library/python
+find "${OUT_PREFIX}" \( -type d -a \( -name test -o -name tests \) \) -exec rm -rf '{}' +
@@ -0,0 +1,27 @@
+#!/usr/bin/env bash
+# Build Path: /app/.heroku/python/
+
+OUT_PREFIX=$1
+BIN_DIR="$(cd "$(dirname "$0")"/../.. || exit; pwd)/bin"
+export BIN_DIR
+
+# shellcheck source=bin/utils
+source "$BIN_DIR/steps/sqlite3"
+
+sqlite3_version
+echo "Setting up SQLite3 Headers for $SQLITE3_VERSION"
+sqlite3_install "$OUT_PREFIX" "$SQLITE3_VERSION" 1
+
+echo "Building Python…"
+SOURCE_TARBALL='https://python.org/ftp/python/2.7.15/Python-2.7.15.tgz'
+curl -L $SOURCE_TARBALL | tar xz
+mv Python-2.7.15 src
+cd src
+
+./configure --prefix=$OUT_PREFIX  --enable-unicode=ucs4 --with-ensurepip=no
+make
+make install
+
+# Remove unneeded test directories, similar to the official Docker Python images:
+# https://github.com/docker-library/python
+find "${OUT_PREFIX}" \( -type d -a \( -name test -o -name tests \) \) -exec rm -rf '{}' +
@@ -4,7 +4,7 @@

 OUT_PREFIX=$1

-echo "Building Python..."
+echo "Building Python…"
 SOURCE_TARBALL='https://python.org/ftp/python/2.7.9/Python-2.7.9.tgz'
 curl -L $SOURCE_TARBALL | tar xz
 mv Python-2.7.9 src
@@ -4,7 +4,7 @@

 OUT_PREFIX=$1

-echo "Building Python..."
+echo "Building Python…"
 SOURCE_TARBALL='https://python.org/ftp/python/3.5.2/Python-3.5.2.tgz'
 curl -L $SOURCE_TARBALL | tar xz
 mv Python-3.5.2 src
@@ -4,7 +4,7 @@

 OUT_PREFIX=$1

-echo "Building Python..."
+echo "Building Python…"
 SOURCE_TARBALL='https://python.org/ftp/python/3.5.3/Python-3.5.3.tgz'
 curl -L $SOURCE_TARBALL | tar xz
 mv Python-3.5.3 src
@@ -4,7 +4,7 @@

 OUT_PREFIX=$1

-echo "Building Python..."
+echo "Building Python…"
 SOURCE_TARBALL='https://python.org/ftp/python/3.6.0/Python-3.6.0.tgz'
 curl -L $SOURCE_TARBALL | tar xz
 mv Python-3.6.0 src
@@ -4,7 +4,7 @@

 OUT_PREFIX=$1

-echo "Building Python..."
+echo "Building Python…"
 SOURCE_TARBALL='https://python.org/ftp/python/3.6.1/Python-3.6.1.tgz'
 curl -L $SOURCE_TARBALL | tar xz
 mv Python-3.6.1 src
@@ -4,7 +4,7 @@

 OUT_PREFIX=$1

-echo "Building Python..."
+echo "Building Python…"
 SOURCE_TARBALL='https://python.org/ftp/python/3.6.2/Python-3.6.2.tgz'
 curl -L $SOURCE_TARBALL | tar xz
 mv Python-3.6.2 src
@@ -14,5 +14,8 @@ cd src
 make
 make install

-ln $OUT_PREFIX/bin/python3 $OUT_PREFIX/bin/python
+# Remove unneeded test directories, similar to the official Docker Python images:
+# https://github.com/docker-library/python
+find "${OUT_PREFIX}" \( -type d -a \( -name test -o -name tests \) \) -exec rm -rf '{}' +

+ln $OUT_PREFIX/bin/python3 $OUT_PREFIX/bin/python
@@ -0,0 +1,21 @@
+#!/usr/bin/env bash
+# Build Path: /app/.heroku/python/
+# Build Deps: libraries/sqlite
+
+OUT_PREFIX=$1
+
+echo "Building Python…"
+SOURCE_TARBALL='https://python.org/ftp/python/3.6.3/Python-3.6.3.tgz'
+curl -L $SOURCE_TARBALL | tar xz
+mv Python-3.6.3 src
+cd src
+
+./configure --prefix=$OUT_PREFIX --with-ensurepip=no
+make
+make install
+
+# Remove unneeded test directories, similar to the official Docker Python images:
+# https://github.com/docker-library/python
+find "${OUT_PREFIX}" \( -type d -a \( -name test -o -name tests \) \) -exec rm -rf '{}' +
+
+ln $OUT_PREFIX/bin/python3 $OUT_PREFIX/bin/python
@@ -0,0 +1,21 @@
+#!/usr/bin/env bash
+# Build Path: /app/.heroku/python/
+# Build Deps: libraries/sqlite
+
+OUT_PREFIX=$1
+
+echo "Building Python…"
+SOURCE_TARBALL='https://python.org/ftp/python/3.6.4/Python-3.6.4.tgz'
+curl -L $SOURCE_TARBALL | tar xz
+mv Python-3.6.4 src
+cd src
+
+./configure --prefix=$OUT_PREFIX --with-ensurepip=no
+make
+make install
+
+# Remove unneeded test directories, similar to the official Docker Python images:
+# https://github.com/docker-library/python
+find "${OUT_PREFIX}" \( -type d -a \( -name test -o -name tests \) \) -exec rm -rf '{}' +
+
+ln $OUT_PREFIX/bin/python3 $OUT_PREFIX/bin/python
@@ -0,0 +1,21 @@
+#!/usr/bin/env bash
+# Build Path: /app/.heroku/python/
+# Build Deps: libraries/sqlite
+
+OUT_PREFIX=$1
+
+echo "Building Python…"
+SOURCE_TARBALL='https://python.org/ftp/python/3.6.5/Python-3.6.5.tgz'
+curl -L $SOURCE_TARBALL | tar xz
+mv Python-3.6.5 src
+cd src
+
+./configure --prefix=$OUT_PREFIX --with-ensurepip=no
+make
+make install
+
+# Remove unneeded test directories, similar to the official Docker Python images:
+# https://github.com/docker-library/python
+find "${OUT_PREFIX}" \( -type d -a \( -name test -o -name tests \) \) -exec rm -rf '{}' +
+
+ln $OUT_PREFIX/bin/python3 $OUT_PREFIX/bin/python
@@ -0,0 +1,29 @@
+#!/usr/bin/env bash
+# Build Path: /app/.heroku/python/
+
+OUT_PREFIX=$1
+BIN_DIR="$(cd "$(dirname "$0")"/../.. || exit; pwd)/bin"
+export BIN_DIR
+
+# shellcheck source=bin/utils
+source "$BIN_DIR/steps/sqlite3"
+
+sqlite3_version
+echo "Setting up SQLite3 Headers for $SQLITE3_VERSION"
+sqlite3_install "$OUT_PREFIX" "$SQLITE3_VERSION" 1
+
+echo "Building Python…"
+SOURCE_TARBALL='https://python.org/ftp/python/3.6.6/Python-3.6.6.tgz'
+curl -L $SOURCE_TARBALL | tar xz
+mv Python-3.6.6 src
+cd src
+
+./configure --prefix=$OUT_PREFIX --with-ensurepip=no
+make
+make install
+
+# Remove unneeded test directories, similar to the official Docker Python images:
+# https://github.com/docker-library/python
+find "${OUT_PREFIX}" \( -type d -a \( -name test -o -name tests \) \) -exec rm -rf '{}' +
+
+ln $OUT_PREFIX/bin/python3 $OUT_PREFIX/bin/python
@@ -0,0 +1,29 @@
+#!/usr/bin/env bash
+# Build Path: /app/.heroku/python/
+
+OUT_PREFIX=$1
+BIN_DIR="$(cd "$(dirname "$0")"/../.. || exit; pwd)/bin"
+export BIN_DIR
+
+# shellcheck source=bin/utils
+source "$BIN_DIR/steps/sqlite3"
+
+sqlite3_version
+echo "Setting up SQLite3 Headers for $SQLITE3_VERSION"
+sqlite3_install "$OUT_PREFIX" "$SQLITE3_VERSION" 1
+
+echo "Building Python…"
+SOURCE_TARBALL='https://python.org/ftp/python/3.7.0/Python-3.7.0.tgz'
+curl -L $SOURCE_TARBALL | tar xz
+mv Python-3.7.0 src
+cd src
+
+./configure --prefix=$OUT_PREFIX --with-ensurepip=no
+make
+make install
+
+# Remove unneeded test directories, similar to the official Docker Python images:
+# https://github.com/docker-library/python
+find "${OUT_PREFIX}" \( -type d -a \( -name test -o -name tests \) \) -exec rm -rf '{}' +
+
+ln $OUT_PREFIX/bin/python3 $OUT_PREFIX/bin/python
@@ -0,0 +1,5 @@
+#!/usr/bin/env bash
+
+sudo apt-get -qq update
+sudo apt-get install software-properties-common
+curl --fail --retry 3 --retry-delay 1 --connect-timeout 3 --max-time 30 https://cli-assets.heroku.com/install-ubuntu.sh | sh
@@ -0,0 +1,38 @@
+#!/bin/bash
+
+set -e
+
+BP_NAME=${1:-"heroku/python"}
+
+curVersion=$(heroku buildpacks:versions "$BP_NAME" | awk 'FNR == 3 { print $1 }')
+newVersion="v$((curVersion + 1))"
+
+read -p "Deploy as version: $newVersion [y/n]? " choice
+case "$choice" in
+  y|Y ) echo "";;
+  n|N ) exit 0;;
+  * ) exit 1;;
+esac
+
+originMaster=$(git rev-parse origin/master)
+echo "Tagging commit $originMaster with $newVersion... "
+git tag "$newVersion" "${originMaster:?}"
+git push origin refs/tags/$newVersion
+
+heroku buildpacks:publish "$BP_NAME" "$newVersion"
+
+if [ $(git tag | grep -q previous-version) ]; then
+    echo "Updating previous-version tag"
+    git tag -d previous-version
+    git push origin :previous-version
+    git tag previous-version latest-version
+fi
+if [ $(git tag | grep -q latest-version) ]; then
+    echo "Updating latest-version tag"
+    git tag -d latest-version
+    git push origin :latest-version
+    git tag latest-version "${originMaster:?}"
+    git push --tags
+fi
+
+echo "Done."
@@ -0,0 +1,5 @@
+{
+  "python": [
+    "heroku/python-getting-started"
+  ]
+}
@@ -0,0 +1,3 @@
+---
+- - "./repos/python/python-getting-started"
+  - f56b90499ec11e1c9576da2f8c7331300e189db3
@@ -1 +1,3 @@
+docopt==0.6.2
 bob-builder==0.0.13
+boto==2.48.0
@@ -0,0 +1,10 @@
+require_relative '../spec_helper'
+
+describe "Python!!!!!!!!!!!" do
+  it "🐍" do
+    Hatchet::Runner.new('python-getting-started', stack: DEFAULT_STACK).deploy do |app|
+      expect(app.output).to           match(/Installing pip/)
+      expect(app.run('python -V')).to match(/3.6.6/)
+    end
+  end
+end
@@ -0,0 +1,23 @@
+ENV['HATCHET_BUILDPACK_BASE'] = 'https://github.com/heroku/heroku-buildpack-python.git'
+
+require 'rspec/core'
+require 'rspec/retry'
+require 'hatchet'
+
+require 'date'
+
+RSpec.configure do |config|
+  config.full_backtrace      = true
+  config.verbose_retry       = true # show retry status in spec process
+  config.default_retry_count = 2 if ENV['IS_RUNNING_ON_CI'] # retry all tests that fail again
+  config.expect_with :rspec do |c|
+    c.syntax = :expect
+  end
+end
+
+if ENV['TRAVIS']
+  # Don't execute tests against "merge" commits
+  exit 0 if ENV['TRAVIS_PULL_REQUEST'] != 'false' && ENV['TRAVIS_BRANCH'] == 'master'
+end
+
+DEFAULT_STACK = 'heroku-16'
@@ -0,0 +1 @@
+apache-airflow==1.10
@@ -0,0 +1 @@
+cffi
@@ -0,0 +1,5 @@
+venv
+*.pyc
+staticfiles
+.env
+db.sqlite3
@@ -0,0 +1,16 @@
+[[source]]
+
+url = "https://pypi.python.org/simple"
+verify_ssl = true
+
+
+[packages]
+
+django = "*"
+gunicorn = "*"
+django-heroku = "*"
+
+
+[requires]
+
+python_version = "3.6"
@@ -0,0 +1,118 @@
+{
+    "_meta": {
+        "hash": {
+            "sha256": "7843aa61794626156c5dbfa26d6be61df24889c396f04a8dead353d23e2899d6"
+        },
+        "host-environment-markers": {
+            "implementation_name": "cpython",
+            "implementation_version": "3.6.3",
+            "os_name": "posix",
+            "platform_machine": "x86_64",
+            "platform_python_implementation": "CPython",
+            "platform_release": "17.3.0",
+            "platform_system": "Darwin",
+            "platform_version": "Darwin Kernel Version 17.3.0: Thu Nov  9 18:09:22 PST 2017; root:xnu-4570.31.3~1/RELEASE_X86_64",
+            "python_full_version": "3.6.3",
+            "python_version": "3.6",
+            "sys_platform": "darwin"
+        },
+        "pipfile-spec": 6,
+        "requires": {
+            "python_version": "3.6"
+        },
+        "sources": [
+            {
+                "url": "https://pypi.python.org/simple",
+                "verify_ssl": true
+            }
+        ]
+    },
+    "default": {
+        "dj-database-url": {
+            "hashes": [
+                "sha256:e16d94c382ea0564c48038fa7fe8d9c890ef1ab1a8ec4cb48e732c124b9482fd",
+                "sha256:a6832d8445ee9d788c5baa48aef8130bf61fdc442f7d9a548424d25cd85c9f08"
+            ],
+            "version": "==0.4.2"
+        },
+        "django": {
+            "hashes": [
+                "sha256:af18618ce3291be5092893d8522fe3919661bf3a1fb60e3858ae74865a4f07c2",
+                "sha256:9614851d4a7ff8cbd32b73c6076441f377c45a5bbff7e771798fb02c43c31f47"
+            ],
+            "version": "==2.0"
+        },
+        "django-heroku": {
+            "hashes": [
+                "sha256:193bacbe644a607642f6b60acd0a382d6abf4a1f7578f8d3eb10659457efe904",
+                "sha256:af6c723872553b7427121a865eb9fce70d566b9ad26d7defcdcd03a8acea56c8"
+            ],
+            "version": "==0.1.0"
+        },
+        "gunicorn": {
+            "hashes": [
+                "sha256:75af03c99389535f218cc596c7de74df4763803f7b63eb09d77e92b3956b36c6",
+                "sha256:eee1169f0ca667be05db3351a0960765620dad53f53434262ff8901b68a1b622"
+            ],
+            "version": "==19.7.1"
+        },
+        "psycopg2": {
+            "hashes": [
+                "sha256:594aa9a095de16614f703d759e10c018bdffeafce2921b8e80a0e8a0ebbc12e5",
+                "sha256:1cf5d84290c771eeecb734abe2c6c3120e9837eb12f99474141a862b9061ac51",
+                "sha256:0344b181e1aea37a58c218ccb0f0f771295de9aa25a625ed076e6996c6530f9e",
+                "sha256:25250867a4cd1510fb755ef9cb38da3065def999d8e92c44e49a39b9b76bc893",
+                "sha256:317612d5d0ca4a9f7e42afb2add69b10be360784d21ce4ecfbca19f1f5eadf43",
+                "sha256:9d6266348b15b4a48623bf4d3e50445d8e581da413644f365805b321703d0fac",
+                "sha256:ddca39cc55877653b5fcf59976d073e3d58c7c406ef54ae8e61ddf8782867182",
+                "sha256:988d2ec7560d42ef0ac34b3b97aad14c4f068792f00e1524fa1d3749fe4e4b64",
+                "sha256:7a9c6c62e6e05df5406e9b5235c31c376a22620ef26715a663cee57083b3c2ea",
+                "sha256:7a75565181e75ba0b9fb174b58172bf6ea9b4331631cfe7bafff03f3641f5d73",
+                "sha256:94e4128ba1ea56f02522fffac65520091a9de3f5c00da31539e085e13db4771b",
+                "sha256:92179bd68c2efe72924a99b6745a9172471931fc296f9bfdf9645b75eebd6344",
+                "sha256:b9358e203168fef7bfe9f430afaed3a2a624717a1d19c7afa7dfcbd76e3cd95c",
+                "sha256:009e0bc09a57dbef4b601cb8b46a2abad51f5274c8be4bba276ff2884cd4cc53",
+                "sha256:d3ac07240e2304181ffdb13c099840b5eb555efc7be9344503c0c03aa681de79",
+                "sha256:40fa5630cd7d237cd93c4d4b64b9e5ed9273d1cfce55241c7f9066f5db70629d",
+                "sha256:6c2f1a76a9ebd9ecf7825b9e20860139ca502c2bf1beabf6accf6c9e66a7e0c3",
+                "sha256:37f54452c7787dbdc0a634ca9773362b91709917f0b365ed14b831f03cbd34ba",
+                "sha256:8f5942a4daf1ffac42109dc4a72f786af4baa4fa702ede1d7c57b4b696c2e7d6",
+                "sha256:bf708455cd1e9fa96c05126e89a0c59b200d086c7df7bbafc7d9be769e4149a3",
+                "sha256:82c40ea3ac1555e0462803380609fbe8b26f52620f3d4f8eb480cfd8ceed8a14",
+                "sha256:207ba4f9125a0a4200691e82d5eee7ea1485708eabe99a07fc7f08696fae62f4",
+                "sha256:0cd4c848f0e9d805d531e44973c8f48962e20eb7fc0edac3db4f9dbf9ed5ab82",
+                "sha256:57baf63aeb2965ca4b52613ce78e968b6d2bde700c97f6a7e8c6c236b51ab83e",
+                "sha256:2954557393cfc9a5c11a5199c7a78cd9c0c793a047552d27b1636da50d013916",
+                "sha256:7c31dade89634807196a6b20ced831fbd5bec8a21c4e458ea950c9102c3aa96f",
+                "sha256:1286dd16d0e46d59fa54582725986704a7a3f3d9aca6c5902a7eceb10c60cb7e",
+                "sha256:697ff63bc5451e0b0db48ad205151123d25683b3754198be7ab5fcb44334e519",
+                "sha256:fc993c9331d91766d54757bbc70231e29d5ceb2d1ac08b1570feaa0c38ab9582",
+                "sha256:9d64fed2681552ed642e9c0cc831a9e95ab91de72b47d0cb68b5bf506ba88647",
+                "sha256:5c3213be557d0468f9df8fe2487eaf2990d9799202c5ff5cb8d394d09fad9b2a"
+            ],
+            "version": "==2.7.3.2"
+        },
+        "pytz": {
+            "hashes": [
+                "sha256:80af0f3008046b9975242012a985f04c5df1f01eed4ec1633d56cc47a75a6a48",
+                "sha256:feb2365914948b8620347784b6b6da356f31c9d03560259070b2f30cff3d469d",
+                "sha256:59707844a9825589878236ff2f4e0dc9958511b7ffaae94dc615da07d4a68d33",
+                "sha256:d0ef5ef55ed3d37854320d4926b04a4cb42a2e88f71da9ddfdacfde8e364f027",
+                "sha256:c41c62827ce9cafacd6f2f7018e4f83a6f1986e87bfd000b8cfbd4ab5da95f1a",
+                "sha256:8cc90340159b5d7ced6f2ba77694d946fc975b09f1a51d93f3ce3bb399396f94",
+                "sha256:dd2e4ca6ce3785c8dd342d1853dd9052b19290d5bf66060846e5dc6b8d6667f7",
+                "sha256:699d18a2a56f19ee5698ab1123bbcc1d269d061996aeb1eda6d89248d3542b82",
+                "sha256:fae4cffc040921b8a2d60c6cf0b5d662c1190fe54d718271db4eb17d44a185b7"
+            ],
+            "version": "==2017.3"
+        },
+        "whitenoise": {
+            "hashes": [
+                "sha256:15f43b2e701821b95c9016cf469d29e2a546cb1c7dead584ba82c36f843995cf",
+                "sha256:9d81515f2b5b27051910996e1e860b1332e354d9e7bcf30c98f21dcb6713e0dd"
+            ],
+            "version": "==3.3.1"
+        }
+    },
+    "develop": {}
+}
@@ -0,0 +1 @@
+web: gunicorn gettingstarted.wsgi
@@ -0,0 +1 @@
+web: python manage.py runserver 0.0.0.0:5000
@@ -0,0 +1,44 @@
+# Python: Getting Started
+
+A barebones Django app, which can easily be deployed to Heroku.
+
+This application supports the [Getting Started with Python on Heroku](https://devcenter.heroku.com/articles/getting-started-with-python) article - check it out.
+
+## Running Locally
+
+Make sure you have Python [installed properly](http://install.python-guide.org). Also, install the [Heroku CLI](https://devcenter.heroku.com/articles/heroku-cli) and [Postgres](https://devcenter.heroku.com/articles/heroku-postgresql#local-setup).
+
+```sh
+$ git clone git@github.com:heroku/python-getting-started.git
+$ cd python-getting-started
+
+$ pipenv install
+
+$ createdb python_getting_started
+
+$ python manage.py migrate
+$ python manage.py collectstatic
+
+$ heroku local
+```
+
+Your app should now be running on [localhost:5000](http://localhost:5000/).
+
+## Deploying to Heroku
+
+```sh
+$ heroku create
+$ git push heroku master
+
+$ heroku run python manage.py migrate
+$ heroku open
+```
+or
+
+[![Deploy](https://www.herokucdn.com/deploy/button.svg)](https://heroku.com/deploy)
+
+## Documentation
+
+For more information about using Python on Heroku, see these Dev Center articles:
+
+- [Python on Heroku](https://devcenter.heroku.com/categories/python)
@@ -0,0 +1,22 @@
+{
+  "name": "Start on Heroku: Python",
+  "description": "A barebones Python app, which can easily be deployed to Heroku.",
+  "image": "heroku/python",
+  "repository": "https://github.com/heroku/python-getting-started",
+  "keywords": ["python", "django" ],
+  "addons": [ "heroku-postgresql" ],
+  "env": {
+    "SECRET_KEY": {
+      "description": "The secret key for the Django application.",
+      "generator": "secret"
+    }
+  },
+  "environments": {
+    "test": {
+      "scripts": {
+        "test-setup": "python manage.py collectstatic --noinput",
+        "test": "python manage.py test"
+      }
+    }
+  }
+}
@@ -0,0 +1,125 @@
+"""
+Django settings for gettingstarted project.
+
+Generated by 'django-admin startproject' using Django 2.0.
+
+For more information on this file, see
+https://docs.djangoproject.com/en/2.0/topics/settings/
+
+For the full list of settings and their values, see
+https://docs.djangoproject.com/en/2.0/ref/settings/
+"""
+
+import os
+import django_heroku
+
+
+# Build paths inside the project like this: os.path.join(BASE_DIR, ...)
+BASE_DIR = os.path.dirname(os.path.dirname(os.path.abspath(__file__)))
+
+
+# Quick-start development settings - unsuitable for production
+# See https://docs.djangoproject.com/en/2.0/howto/deployment/checklist/
+
+# SECURITY WARNING: keep the secret key used in production secret!
+SECRET_KEY = 'CHANGE_ME!!!! (P.S. the SECRET_KEY environment variable will be used, if set, instead).'
+
+# SECURITY WARNING: don't run with debug turned on in production!
+DEBUG = True
+
+ALLOWED_HOSTS = []
+
+
+# Application definition
+
+INSTALLED_APPS = [
+    'django.contrib.admin',
+    'django.contrib.auth',
+    'django.contrib.contenttypes',
+    'django.contrib.sessions',
+    'django.contrib.messages',
+    'django.contrib.staticfiles',
+    'hello'
+]
+
+MIDDLEWARE = [
+    'django.middleware.security.SecurityMiddleware',
+    'django.contrib.sessions.middleware.SessionMiddleware',
+    'django.middleware.common.CommonMiddleware',
+    'django.middleware.csrf.CsrfViewMiddleware',
+    'django.contrib.auth.middleware.AuthenticationMiddleware',
+    'django.contrib.messages.middleware.MessageMiddleware',
+    'django.middleware.clickjacking.XFrameOptionsMiddleware',
+]
+
+ROOT_URLCONF = 'gettingstarted.urls'
+
+TEMPLATES = [
+    {
+        'BACKEND': 'django.template.backends.django.DjangoTemplates',
+        'DIRS': [],
+        'APP_DIRS': True,
+        'OPTIONS': {
+            'context_processors': [
+                'django.template.context_processors.debug',
+                'django.template.context_processors.request',
+                'django.contrib.auth.context_processors.auth',
+                'django.contrib.messages.context_processors.messages',
+            ],
+        },
+    },
+]
+
+WSGI_APPLICATION = 'gettingstarted.wsgi.application'
+
+
+# Database
+# https://docs.djangoproject.com/en/2.0/ref/settings/#databases
+
+DATABASES = {
+    'default': {
+        'ENGINE': 'django.db.backends.sqlite3',
+        'NAME': os.path.join(BASE_DIR, 'db.sqlite3'),
+    }
+}
+
+
+# Password validation
+# https://docs.djangoproject.com/en/2.0/ref/settings/#auth-password-validators
+
+AUTH_PASSWORD_VALIDATORS = [
+    {
+        'NAME': 'django.contrib.auth.password_validation.UserAttributeSimilarityValidator',
+    },
+    {
+        'NAME': 'django.contrib.auth.password_validation.MinimumLengthValidator',
+    },
+    {
+        'NAME': 'django.contrib.auth.password_validation.CommonPasswordValidator',
+    },
+    {
+        'NAME': 'django.contrib.auth.password_validation.NumericPasswordValidator',
+    },
+]
+
+
+# Internationalization
+# https://docs.djangoproject.com/en/2.0/topics/i18n/
+
+LANGUAGE_CODE = 'en-us'
+
+TIME_ZONE = 'UTC'
+
+USE_I18N = True
+
+USE_L10N = True
+
+USE_TZ = True
+
+
+# Static files (CSS, JavaScript, Images)
+# https://docs.djangoproject.com/en/2.0/howto/static-files/
+
+STATIC_URL = '/static/'
+
+django_heroku.settings(locals())
@@ -0,0 +1,17 @@
+from django.conf.urls import include, url
+from django.urls import path
+
+from django.contrib import admin
+admin.autodiscover()
+
+import hello.views
+
+# Examples:
+# url(r'^$', 'gettingstarted.views.home', name='home'),
+# url(r'^blog/', include('blog.urls')),
+
+urlpatterns = [
+    url(r'^$', hello.views.index, name='index'),
+    url(r'^db', hello.views.db, name='db'),
+    path('admin/', admin.site.urls),
+]
@@ -0,0 +1,15 @@
+"""
+WSGI config for gettingstarted project.
+
+It exposes the WSGI callable as a module-level variable named ``application``.
+
+For more information on this file, see
+https://docs.djangoproject.com/en/1.6/howto/deployment/wsgi/
+"""
+
+import os
+os.environ.setdefault("DJANGO_SETTINGS_MODULE", "gettingstarted.settings")
+
+from django.core.wsgi import get_wsgi_application
+
+application = get_wsgi_application()
@@ -0,0 +1,3 @@
+from django.contrib import admin
+
+# Register your models here.
@@ -0,0 +1,23 @@
+# -*- coding: utf-8 -*-
+# Generated by Django 1.9.1 on 2016-01-27 21:54
+from __future__ import unicode_literals
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    initial = True
+
+    dependencies = [
+    ]
+
+    operations = [
+        migrations.CreateModel(
+            name='Greeting',
+            fields=[
+                ('id', models.AutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID')),
+                ('when', models.DateTimeField(auto_now_add=True, verbose_name=b'date created')),
+            ],
+        ),
+    ]
@@ -0,0 +1,5 @@
+from django.db import models
+
+# Create your models here.
+class Greeting(models.Model):
+    when = models.DateTimeField('date created', auto_now_add=True)
@@ -0,0 +1,83 @@
+<!DOCTYPE html>
+<html>
+<head>
+<title>Python Getting Started on Heroku</title>
+  <link rel="stylesheet" type="text/css" href="//maxcdn.bootstrapcdn.com/bootstrap/3.3.4/css/bootstrap.min.css" />
+  <script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.3/jquery.min.js"></script>
+  <script type="text/javascript" src="//maxcdn.bootstrapcdn.com/bootstrap/3.3.4/js/bootstrap.min.js"></script>
+  <style type="text/css">
+    .jumbotron {
+        background: #532f8c;
+        color: white;
+        padding-bottom: 80px
+    }
+    .jumbotron .btn-primary {
+        background: #845ac7;
+        border-color: #845ac7
+    }
+    .jumbotron .btn-primary:hover {
+        background: #7646c1
+    }
+    .jumbotron p {
+        color: #d9ccee;
+        max-width: 75%;
+        margin: 1em auto 2em
+    }
+    .navbar+.jumbotron {
+        margin-top: -20px
+    }
+    .jumbotron .lang-logo {
+        display: block;
+        background: #b01302;
+        border-radius: 50%;
+        overflow: hidden;
+        width: 100px;
+        height: 100px;
+        margin: auto;
+        border: 2px solid white
+    }
+    .jumbotron .lang-logo img {
+        max-width: 100%
+    }
+
+
+  </style>
+</head>
+<body>
+<nav class="navbar navbar-default navbar-static-top navbar-inverse">
+  <div class="container">
+    <ul class="nav navbar-nav">
+      <li class="active">
+        <a href="/"><span class="glyphicon glyphicon-home"></span> Home</a>
+      </li>
+      <li>
+        <a href="https://devcenter.heroku.com/articles/how-heroku-works"><span class="glyphicon glyphicon-user"></span> How Heroku Works</a>
+      </li>
+      <li class="dropdown">
+        <a href="#" class="dropdown-toggle" data-toggle="dropdown" role="button" aria-expanded="false"><span class="glyphicon glyphicon-info-sign"></span> Getting Started Guides <span class="caret"></span></a>
+          <ul class="dropdown-menu" role="menu">
+            <li><a href="https://devcenter.heroku.com/articles/getting-started-with-ruby">Getting Started with Ruby on Heroku</a></li>
+            <li><a href="https://devcenter.heroku.com/articles/getting-started-with-nodejs">Getting Started with Node on Heroku</a></li>
+            <li><a href="https://devcenter.heroku.com/articles/getting-started-with-php">Getting Started with PHP on Heroku</a></li>
+            <li><a href="https://devcenter.heroku.com/articles/getting-started-with-python">Getting Started with Python on Heroku</a></li>
+            <li><a href="https://devcenter.heroku.com/articles/getting-started-with-java">Getting Started with Java on Heroku</a></li>
+            <li><a href="https://devcenter.heroku.com/articles/getting-started-with-clojure">Getting Started with Clojure on Heroku</a></li>
+            <li><a href="https://devcenter.heroku.com/articles/getting-started-with-scala">Getting Started with Scala on Heroku</a></li>
+            <li class="divider"></li>
+            <li><a href="https://devcenter.heroku.com/articles/getting-started-with-heroku-and-connect-without-local-dev">Getting Started on Heroku with Heroku Connect</a></li>
+            <li><a href="https://devcenter.heroku.com/articles/getting-started-with-jruby">Getting Started with Ruby on Heroku (Microsoft Windows)</a></li>
+          </ul>
+      </li>
+    </ul>
+    <ul class="nav navbar-nav navbar-right">
+      <li class="navbar-right">
+        <a href="https://devcenter.heroku.com"><span class="glyphicon glyphicon-book"></span> Heroku Dev Center</a>
+      </li>
+    </ul>
+  </div>
+</nav>
+
+{% block content %}{% endblock %}
+
+</body>
+</html>
@@ -0,0 +1,21 @@
+{% extends "base.html" %}
+{% load staticfiles %}
+
+{% block content %}
+  <div class="container">
+
+
+<h2>Page View Report</h2>
+
+
+<ul>
+
+{% for greeting in greetings %}
+    <li>{{ greeting.when }}</li>
+{% endfor %}
+
+</ul>
+
+</div>
+
+{% endblock %}
@@ -0,0 +1,58 @@
+{% extends "base.html" %}
+{% load staticfiles %}
+
+{% block content %}
+
+<div class="jumbotron text-center">
+  <div class="container">
+    <a href="/" class="lang-logo">
+      <img src="{% static 'lang-logo.png'%}">
+    </a>
+    <h1>Getting Started with Python on Heroku</h1>
+    <p>This is a sample Python application deployed to Heroku. It's a reasonably simple app - but a good foundation for understanding how to get the most out of the Heroku platform.</p>
+    <a type="button" class="btn btn-lg btn-default" href="https://devcenter.heroku.com/articles/getting-started-with-python"><span class="glyphicon glyphicon-flash"></span> Getting Started with Python</a>
+    <a type="button" class="btn btn-lg btn-primary" href="https://github.com/heroku/python-getting-started"><span class="glyphicon glyphicon-download"></span> Source on GitHub</a>
+  </div>
+</div>
+<div class="container">
+  <div class="alert alert-info text-center" role="alert">
+    To deploy your own copy, and learn the fundamentals of the Heroku platform, head over to the <a href="https://devcenter.heroku.com/articles/getting-started-with-python" class="alert-link">Getting Started with Python on Heroku</a> tutorial.
+  </div>
+  <hr>
+  <div class="row">
+    <div class="col-md-6">
+      <h3><span class="glyphicon glyphicon-info-sign"></span> How this sample app works</h3>
+      <ul>
+        <li>This app was deployed to Heroku, either using Git or by using <a href="https://github.com/heroku/python-getting-started">Heroku Button</a> on the repository.</li>
+
+        <li>When Heroku received the source code, it fetched all the dependencies in the <a href="https://github.com/heroku/python-getting-started/blob/master/Pipfile">Pipfile</a>, creating a deployable slug.</li>
+        <li>The platform then spins up a dyno, a lightweight container that provides an isolated environment in which the slug can be mounted and executed.</li>
+        <li>You can scale your app, manage it, and deploy over <a href="https://addons.heroku.com/">150 add-on services</a>, from the Dashboard or CLI.</li>
+      </ul>
+    </div>
+    <div class="col-md-6">
+      <h3><span class="glyphicon glyphicon-link"></span> Next Steps</h3>
+      <ul>
+        <li>If you are following the <a href="https://devcenter.heroku.com/articles/getting-started-with-python">Getting Started</a> guide, then please head back to the tutorial and follow the next steps!</li>
+        <li>If you deployed this app by deploying the Heroku Button, then in a command line shell, run:</li>
+        <ul>
+          <li><code>git clone https://github.com/heroku/python-getting-started.git</code> - this will create a local copy of the source code for the app</li>
+          <li><code>cd python-getting-started</code> - change directory into the local source code repository</li>
+          <li><code>heroku git:remote -a &lt;your-app-name></code> - associate the Heroku app with the repository</li>
+          <li>You'll now be set up to run the app locally, or <a href="https://devcenter.heroku.com/articles/getting-started-with-python#push-local-changes">deploy changes</a> to Heroku</li>
+        </ul>
+      </ul>
+      <h3><span class="glyphicon glyphicon-link"></span> Helpful Links</h3>
+      <ul>
+        <li><a href="https://www.heroku.com/home">Heroku</a></li>
+        <li><a href="https://devcenter.heroku.com/">Heroku Dev Center</a></li>
+        <li><a href="https://devcenter.heroku.com/articles/getting-started-with-python">Getting Started with Python on Heroku</a></li>
+        <li><a href="https://devcenter.heroku.com/articles/django-app-configuration">Configuring Django Apps for Heroku</a></li>
+      </ul>
+    </div>
+  </div> <!-- row -->
+   <div class="alert alert-info text-center" role="alert">
+    Please do work through the Getting Started guide, even if you do know how to build such an application.  The guide covers the basics of working with Heroku, and will familiarize you with all the concepts you need in order to build and deploy your own apps.
+  </div>
+</div>
+{% endblock %}
@@ -0,0 +1,18 @@
+from django.contrib.auth.models import AnonymousUser, User
+from django.test import TestCase, RequestFactory
+
+from .views import index
+
+class SimpleTest(TestCase):
+    def setUp(self):
+        # Every test needs access to the request factory.
+        self.factory = RequestFactory()
+
+    def test_details(self):
+        # Create an instance of a GET request.
+        request = self.factory.get('/')
+        request.user = AnonymousUser()
+
+        # Test my_view() as if it were deployed at /customer/details
+        response = index(request)
+        self.assertEqual(response.status_code, 200)
--- a/Show More
+++ b/Show More
				`@@ -0,0 +1 @@`
				`web: python manage.py runserver 0.0.0.0:5000`