changelog

Signed-off-by: Kenneth Reitz <me@kennethreitz.org>

.gitignore

@@ -1,3 +1,5 @@
 *.pyc
 site
 .DS_Store
+
+/.envrc

.travis.yml

@@ -1,9 +1,23 @@
 language: bash
-sudo: required
-services:
-  - docker
-# install: docker pull heroku/cedar:14
-script: ./tests.sh
-env:
-  - STACK=heroku-16
-  - STACK=cedar-14
+dist: trusty
+jobs:
+  include:
+    - stage: "Bash linting (shellcheck)"
+      sudo: false
+      addons:
+        apt:
+          sources:
+          - debian-sid    # Grab shellcheck from the Debian repo (o_O)
+          packages:
+          - shellcheck
+      script: make check
+
+    - stage: "Stack Tests"
+      services: docker
+      env: STACK=heroku-16
+      script: ./tests.sh
+
+    - stage: "Stack Tests"
+      services: docker
+      env: STACK=cedar-14
+      script: ./tests.sh

CHANGELOG.md

@@ -1,8 +1,59 @@
 # Python Buildpack Changelog
 
+# 118
+
+Improvements to Pipenv support.
+
+# 117
+
+Bug fix.
+
+# 116
+
+Vendoring improvements.
+
+- Geos libraries should work on Heroku-16 now.
+- The libffi/libmemcached vendoring step is now skipped on Heroku-16 (since they are installed in the base image).
+
+# 115
+
+Revert a pull request.
+
+- No longer using `sub_env` for `pip install` step.
+
+# 114
+
+- Bugfixes.
+
+Blacklisting `PYTHONHOME` and `PYTHONPATH` for older apps. Upgrades to nltk support.
+
+# 113
+
+Updates to Pipenv support.
+
+# 112
+
+Bugfix.
+
+- Fixed grep output bug.
+
+# 111
+
+Linting, bugfixes.
+
+# 110
+
+Update default Python to 3.6.2.
+
+# 109
+
+Update Default Python to 3.6.1, bugfixes.
+
+- Fixed automatic pip uninstall of dependencies removed from requirements.txt.
+
 # 108
 
-Updated setuptools.
+Fix output for collectstatic step.
 
 # 107
 

LICENSE

@@ -1,6 +1,6 @@
 MIT License:
 
-Copyright (C) 2016 Heroku, Inc.
+Copyright (C) 2017 Heroku, Inc.
 
 Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
 

Makefile

@@ -1,7 +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/cryptography 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)..."

README.md

@@ -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/en/latest/), [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 (e.g. scipy) are [not compatible](https://devcenter.heroku.com/articles/python-c-deps).
+Some Python packages with obscure C dependencies are [not compatible](https://devcenter.heroku.com/articles/python-c-deps).
 
 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		Procfile	web.py
 
     $ heroku create --buildpack heroku/python
 
     $ git push heroku master
     ...
     -----> Python app detected
-    -----> Installing python-2.7.13
-         $ 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-3.6.2
+    -----> Installing pip
+    -----> Installing requirements with latest pipenv...
+           ...
+           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:
 
@@ -46,11 +44,11 @@ Specify a Python Runtime
 Specific versions of the Python runtime can be specified with a `runtime.txt` file:
 
     $ cat runtime.txt
-    python-3.6.1
+    python-2.7.13
 
 Runtime options include:
 
+- `python-3.6.2`
 - `python-2.7.13`
-- `python-3.6.1`
 - `pypy-5.7.1` (unsupported, experimental)
 - `pypy3-5.5.1` (unsupported, experimental)

bin/compile

@@ -25,20 +25,24 @@ export BUILDPACK_LOG_FILE=${BUILDPACK_LOG_FILE:-/dev/null}
 export PATH=:/usr/local/bin:$PATH
 
 # Paths.
-BIN_DIR=$(cd $(dirname $0); pwd) # absolute path
-ROOT_DIR=$(dirname $BIN_DIR)
+BIN_DIR=$(cd "$(dirname "$0")"; pwd) # absolute path
+ROOT_DIR=$(dirname "$BIN_DIR")
 BUILD_DIR=$1
 CACHE_DIR=$2
 ENV_DIR=$3
 
+export BUILD_DIR CACHE_DIR ENV_DIR
+
 # Python defaults
-DEFAULT_PYTHON_VERSION="python-2.7.13"
+DEFAULT_PYTHON_VERSION="python-3.6.2"
 DEFAULT_PYTHON_STACK="cedar-14"
-PYTHON_EXE="/app/.heroku/python/bin/python"
-PIP_VERSION="9.0.1"
+PIP_UPDATE="9.0.1"
+
+export DEFAULT_PYTHON_VERSION DEFAULT_PYTHON_STACK PIP_UPDATE
 
 # Common Problem Warnings
-export WARNINGS_LOG=$(mktemp)
+WARNINGS_LOG=$(mktemp)
+export WARNINGS_LOG
 export RECOMMENDED_PYTHON_VERSION=$DEFAULT_PYTHON_VERSION
 
 # Setup vendored tools and pip-pop (pip-diff)
@@ -55,10 +59,12 @@ unset RECEIVE_DATA RUN_KEY BUILD_INFO DEPLOY LOG_TOKEN
 unset CYTOKINE_LOG_FILE GEM_PATH
 
 # Syntax sugar.
-source $BIN_DIR/utils
+# shellcheck source=bin/utils
+source "$BIN_DIR/utils"
 
 # Import collection of warnings.
-source $BIN_DIR/warnings
+# shellcheck source=bin/warnings
+source "$BIN_DIR/warnings"
 
 # we need to put a bunch of symlinks in there later
 mkdir -p /app/.heroku
@@ -83,7 +89,7 @@ export LD_LIBRARY_PATH=/app/.heroku/vendor/lib:/app/.heroku/python/lib:$LD_LIBRA
 export PKG_CONFIG_PATH=/app/.heroku/vendor/lib/pkg-config:/app/.heroku/python/lib/pkg-config:$PKG_CONFIG_PATH
 
 # Switch to the repo's context.
-cd $BUILD_DIR
+cd "$BUILD_DIR"
 
 # Warn for lack of Procfile.
 if [[ ! -f Procfile ]]; then
@@ -92,60 +98,66 @@ if [[ ! -f Procfile ]]; then
 fi
 
 # Prepare the cache.
-mkdir -p $CACHE_DIR
+mkdir -p "$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 $CACHE_DIR/.heroku/src .heroku/ &> /dev/null || true
+cp -R "$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
 fi
 
 # Experimental pre_compile hook.
-source $BIN_DIR/steps/hooks/pre_compile
+# shellcheck source=bin/steps/hooks/pre_compile
+source "$BIN_DIR/steps/hooks/pre_compile"
 
 # Sticky runtimes.
-if [ -f $CACHE_DIR/.heroku/python-version ]; then
-  DEFAULT_PYTHON_VERSION=$(cat $CACHE_DIR/.heroku/python-version)
+if [ -f "$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 $CACHE_DIR/.heroku/python-stack)
+if [ -f "$CACHE_DIR/.heroku/python-stack" ]; then
+  CACHED_PYTHON_STACK=$(cat "$CACHE_DIR/.heroku/python-stack")
 else
   CACHED_PYTHON_STACK=$STACK
 fi
 
+export CACHED_PYTHON_STACK
+
 # Pipenv Python version support.
-source $BIN_DIR/steps/pipenv-python-version
+# shellcheck source=bin/steps/pipenv-python-version
+source "$BIN_DIR/steps/pipenv-python-version"
 
 # If no runtime given, assume default version.
 if [ ! -f runtime.txt ]; then
-  echo $DEFAULT_PYTHON_VERSION > runtime.txt
+  echo "$DEFAULT_PYTHON_VERSION" > runtime.txt
 fi
 
-mkdir -p $(dirname $PROFILE_PATH)
+mkdir -p "$(dirname "$PROFILE_PATH")"
 mkdir -p /app/.heroku/src
 
 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 $BIN_DIR/steps/python
+# shellcheck source=bin/steps/python
+source "$BIN_DIR/steps/python"
 mtime "python.install.time" "${start}"
 
 # Pipenv support.
-source $BIN_DIR/steps/pipenv
+# shellcheck source=bin/steps/pipenv
+source "$BIN_DIR/steps/pipenv"
 
 # If no requirements.txt file given, assume `setup.py develop` is intended.
 if [ ! -f requirements.txt ] && [ ! -f Pipfile ]; then
@@ -153,88 +165,101 @@ if [ ! -f requirements.txt ] && [ ! -f Pipfile ]; then
 fi
 
 # Fix egg-links.
-source $BIN_DIR/steps/eggpath-fix
+# shellcheck source=bin/steps/eggpath-fix
+source "$BIN_DIR/steps/eggpath-fix"
 
 # Mercurial support.
-source $BIN_DIR/steps/mercurial
+# shellcheck source=bin/steps/mercurial
+source "$BIN_DIR/steps/mercurial"
 
 # Pylibmc support.
-source $BIN_DIR/steps/pylibmc
+# shellcheck source=bin/steps/pylibmc
+source "$BIN_DIR/steps/pylibmc"
 
 # Libffi support.
-source $BIN_DIR/steps/cryptography
+# shellcheck source=bin/steps/cryptography
+source "$BIN_DIR/steps/cryptography"
 
 # Support for Geo libraries.
-sub-env $BIN_DIR/steps/geo-libs
+# shellcheck source=bin/steps/geo-libs
+sub_env "$BIN_DIR/steps/geo-libs"
 
 # GDAL support.
-source $BIN_DIR/steps/gdal
-
-# Install dependencies with Pip (where the magic happens).
-let start=$(nowms)
-source $BIN_DIR/steps/pip-install
-mtime "pip.install.time" "${start}"
+# shellcheck source=bin/steps/gdal
+source "$BIN_DIR/steps/gdal"
 
 # Uninstall removed dependencies with Pip.
 let start=$(nowms)
-source $BIN_DIR/steps/pip-uninstall
+# shellcheck source=bin/steps/pip-uninstall
+source "$BIN_DIR/steps/pip-uninstall"
 mtime "pip.uninstall.time" "${start}"
 
+# Install dependencies with Pip (where the magic happens).
+let 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 $BIN_DIR/steps/nltk
+sub_env "$BIN_DIR/steps/nltk"
 mtime "nltk.download.time" "${start}"
 
 # Support for pip install -e.
 # 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 $BIN_DIR/steps/collectstatic
+sub_env "$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/
+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/
 
 # 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 $BIN_DIR/steps/hooks/post_compile
+# shellcheck source=bin/steps/hooks/post_compile
+source "$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.
 
-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)"

bin/detect

@@ -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
 

bin/release

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

bin/steps/collectstatic

@@ -10,6 +10,7 @@
 #   - $DISABLE_COLLECTSTATIC: disables this functionality.
 #   - $DEBUG_COLLECTSTATIC: upon failure, print out environment variables.
 
+# shellcheck source=bin/utils
 source $BIN_DIR/utils
 
 # Location of 'manage.py', if it exists.
@@ -20,7 +21,7 @@ MANAGE_FILE=${MANAGE_FILE:-fakepath}
 [ -f .heroku/collectstatic_disabled ] && DISABLE_COLLECTSTATIC=1
 
 # Ensure that Django is explicitly specified in requirements.txt
-sp-grep django && DJANGO_INSTALLED=1
+sp-grep -s django && DJANGO_INSTALLED=1
 
 
 if [ ! "$DISABLE_COLLECTSTATIC" ] && [ -f "$MANAGE_FILE" ] && [ "$DJANGO_INSTALLED" ]; then
@@ -29,13 +30,13 @@ if [ ! "$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
+    python "$MANAGE_FILE" collectstatic --noinput --traceback 2>&1 | sed '/^Post-processed/d;/^Copying/d;/^$/d' | indent
     COLLECTSTATIC_STATUS="${PIPESTATUS[0]}"
 
     set -e
 
     # Display a warning if collectstatic failed.
-    [ $COLLECTSTATIC_STATUS -ne 0 ] && {
+    [ "$COLLECTSTATIC_STATUS" -ne 0 ] && {
 
         echo
         echo " !     Error while running '$ python $MANAGE_FILE collectstatic --noinput'."

bin/steps/cryptography

@@ -1,6 +1,6 @@
 #!/usr/bin/env bash
 
-# This script serves as the Cryptography build step of the
+# This script serves as the cffi build step of the
 # [**Python Buildpack**](https://github.com/heroku/heroku-buildpack-python)
 # compiler.
 #
@@ -9,13 +9,19 @@
 #
 # This script is invoked by [`bin/compile`](/).
 
+if [[ "$STACK" == "heroku-16" ]]; then
+    # libffi is pre-installed in the stack image so there is no need to vendor it.
+    return 0
+fi
+
 # The location of the pre-compiled libffi binary.
 VENDORED_LIBFFI="https://lang-python.s3.amazonaws.com/$STACK/libraries/vendor/libffi.tar.gz"
 
 PKG_CONFIG_PATH="/app/.heroku/vendor/lib/pkgconfig:$PKG_CONFIG_PATH"
 
 # Syntax sugar.
-source $BIN_DIR/utils
+# shellcheck source=bin/utils
+source "$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
@@ -24,8 +30,9 @@ if (pip-grep -s requirements.txt argon2-cffi bcrypt cffi cryptography django[arg
     echo "-----> Noticed cffi. Bootstrapping libffi."
     mkdir -p .heroku/vendor
     # Download and extract libffi into target vendor directory.
-    curl $VENDORED_LIBFFI -s | tar zxv -C .heroku/vendor &> /dev/null
+    curl "$VENDORED_LIBFFI" -s | tar zxv -C .heroku/vendor &> /dev/null
   fi
 
-  export LIBFFI=$(pwd)/vendor
+  LIBFFI=$(pwd)/vendor
+  export LIBFFI
 fi

bin/steps/eggpath-fix

@@ -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

bin/steps/eggpath-fix2

@@ -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

bin/steps/gdal

@@ -15,7 +15,8 @@ VENDORED_GDAL="https://lang-python.s3.amazonaws.com/$STACK/libraries/vendor/gdal
 PKG_CONFIG_PATH="/app/.heroku/vendor/lib/pkgconfig:$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
 

bin/steps/geo-libs

@@ -17,7 +17,8 @@ VENDORED_PROJ="https://lang-python.s3.amazonaws.com/$STACK/libraries/vendor/proj
 PKG_CONFIG_PATH="/app/.heroku/vendor/lib/pkgconfig:$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 [[ "$BUILD_WITH_GEO_LIBRARIES" ]]; then
@@ -26,11 +27,18 @@ if [[ "$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
 fi
 

bin/steps/hooks/post_compile

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

bin/steps/hooks/pre_compile

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

bin/steps/mercurial

@@ -1,3 +1,5 @@
+#!/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

bin/steps/nltk

@@ -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 [ $? -eq 0 ]; then
+if sp-grep -s nltk; then
     puts-step "Downloading NLTK corpora..."
+
     nltk_packages_definition="$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
-

bin/steps/pip-install

@@ -1,10 +1,13 @@
+#!/usr/bin/env bash
+
 if [ ! "$SKIP_PIP_INSTALL" ]; then
 
     # Install dependencies with Pip.
     puts-step "Installing requirements with pip"
 
     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 $WARNINGS_LOG | cleanup | indent
+
+    /app/.heroku/python/bin/pip install -r "$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
 
@@ -20,4 +23,4 @@ if [ ! "$SKIP_PIP_INSTALL" ]; then
     /app/.heroku/python/bin/pip freeze --disable-pip-version-check > .heroku/python/requirements-installed.txt
 
     echo
-fi
+fi

bin/steps/pip-uninstall

@@ -1,3 +1,5 @@
+#!/usr/bin/env bash
+
 set +e
 # Install dependencies with Pip.
 

bin/steps/pipenv

@@ -1,13 +1,20 @@
+#!/usr/bin/env bash
+
 # Pipenv support (Generate requriements.txt with pipenv).
 if [[ -f Pipfile ]]; then
     if [[ ! -f requirements.txt ]]; then
-        puts-step "Installing requirements with latest pipenv..."
+        puts-step "Installing requirements with latest Pipenv..."
 
         # Install pipenv.
         /app/.heroku/python/bin/pip install pipenv --upgrade &> /dev/null
 
+        if [[ ! -f Pipfile.lock ]]; then
+            /app/.heroku/python/bin/pipenv install --system --skip-lock 2>&1 | indent
+        else
+            /app/.heroku/python/bin/pipenv install --system 2>&1 | indent
+        fi
         # Install the dependencies.
-        /app/.heroku/python/bin/pipenv install --system 2>&1 | indent
+
 
         # Skip pip install, later.
         export SKIP_PIP_INSTALL=1
@@ -16,4 +23,4 @@ if [[ -f Pipfile ]]; then
         /app/.heroku/python/bin/pip freeze > requirements.txt
 
     fi
-fi
+fi

bin/steps/pipenv-python-version

@@ -1,6 +1,8 @@
+#!/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
@@ -8,14 +10,14 @@ if [[ -f $BUILD_DIR/Pipfile.lock ]]; then
         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_version' "$BUILD_DIR/Pipfile.lock")
             set -e
 
             if [ "$PYTHON" = 2.7 ]; then
-                echo "python-2.7.13" > $BUILD_DIR/runtime.txt
+                echo "python-2.7.13" > "$BUILD_DIR/runtime.txt"
             fi
             if [ "$PYTHON" = 3.6 ]; then
-                echo "python-3.6.0" > $BUILD_DIR/runtime.txt
+                echo "python-3.6.2" > "$BUILD_DIR/runtime.txt"
             fi
         fi
     fi

bin/steps/pylibmc

@@ -9,12 +9,17 @@
 #
 # This script is invoked by [`bin/compile`](/).
 
+if [[ "$STACK" == "heroku-16" ]]; then
+    # libmemcached is pre-installed in the stack image so there is no need to vendor it.
+    return 0
+fi
+
 # The location of the pre-compiled libmemcached binary.
 VENDORED_MEMCACHED="https://lang-python.s3.amazonaws.com/$STACK/libraries/vendor/libmemcache.tar.gz"
 
 # 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

bin/steps/python

@@ -1,10 +1,16 @@
+#!/usr/bin/env bash
+
 set +e
 runtime-fixer runtime.txt
 PYTHON_VERSION=$(cat runtime.txt)
 
-# Install Python.
+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
+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
@@ -12,41 +18,30 @@ 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"
 
     # 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 [[ $? != 0 ]] ; then
+    if ! curl "https://lang-python.s3.amazonaws.com/$STACK/runtimes/$PYTHON_VERSION.tar.gz" -s | tar zxv -C .heroku/python &> /dev/null; then
       puts-warn "Requested runtime ($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 $TMPTARDIR" RETURN
+if [ "$FRESH_PYTHON" ] || [[ ! $(pip --version) == *$PIP_UPDATE* ]]; then
 
   puts-step "Installing pip"
 
@@ -54,7 +49,7 @@ if [ "$FRESH_PYTHON" ] || [[ ! $(pip --version) == *$PIP_VERSION* ]]; then
   rm -fr /app/.heroku/python/lib/python2.7/site-packages/pip-*
   rm -fr /app/.heroku/python/lib/python2.7/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" &> /dev/null
 
 fi
 

bin/test-compile

@@ -1,10 +1,12 @@
 #!/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"
+
+DISABLE_COLLECTSTATIC=1 "$(dirname "${0:-}")/compile" "$1" "$2" "$3"
 
 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

bin/utils

@@ -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 +53,8 @@ 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}')"
 }
 

bin/warnings

@@ -1,3 +1,4 @@
+#!/usr/bin/env bash
 shopt -s extglob
 
 old-platform() {

builds/libraries/vendor/gdal

@@ -10,14 +10,15 @@ hash -r
 
 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

builds/libraries/vendor/geos

@@ -10,14 +10,16 @@ hash -r
 
 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

builds/libraries/vendor/proj

@@ -10,14 +10,15 @@ hash -r
 
 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

builds/runtimes/pypy-5.8.0

@@ -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

builds/runtimes/pypy3-5.8.0

@@ -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/pypy3-v5.8.0-linux64.tar.bz2'
+curl -L $SOURCE_TARBALL | tar jx
+cp -R pypy3-v5.8.0-linux64/* $OUT_PREFIX
+
+ln $OUT_PREFIX/bin/pypy3 $OUT_PREFIX/bin/python

builds/runtimes/python-2.7.13

@@ -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 '{}' +

builds/runtimes/python-3.6.2

@@ -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/3.6.2/Python-3.6.2.tgz'
+curl -L $SOURCE_TARBALL | tar xz
+mv Python-3.6.2 src
+cd src
+
+./configure --prefix=$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

test/fixtures/cffi/requirements.txt

@@ -0,0 +1 @@
+cffi

test/fixtures/geos/requirements.txt

@@ -0,0 +1 @@
+django

test/fixtures/nltk/nltk.txt

@@ -1 +1,2 @@
-wordnet
+city_database
+stopwords

test/fixtures/nltk/runtime.txt

@@ -0,0 +1 @@
+python-2.7.13

test/fixtures/pylibmc/requirements.txt

@@ -0,0 +1 @@
+pylibmc

test/fixtures/python3/runtime.txt

@@ -1 +0,0 @@
-python-3.6.0

test/run

@@ -1,6 +1,5 @@
 #!/usr/bin/env bash
 
-
 testPipenv() {
   compile "pipenv"
   assertCapturedSuccess
@@ -8,7 +7,7 @@ testPipenv() {
 
 testPipenvVersion() {
   compile "pipenv-version"
-  assertCaptured "3.6.0"
+  assertCaptured "3.6.2"
   assertCapturedSuccess
 }
 
@@ -17,13 +16,17 @@ testNoRequirements() {
   assertCapturedError
 }
 
-
-testNLTK() {
-  compile "nltk"
-  assertCaptured "wordnet"
+testGEOS() {
+  BUILD_WITH_GEO_LIBRARIES=1 compile "geos"
+  assertCaptured "geos"
   assertCapturedSuccess
 }
 
+testNLTK() {
+  compile "nltk"
+  assertCaptured "Downloading NLTK packages: city_database stopwords"
+  assertCapturedSuccess
+}
 
 testSetupPy() {
   compile "setup-py"
@@ -44,6 +47,18 @@ testPsycopg2() {
   assertCapturedSuccess
 }
 
+testCffi() {
+  compile "cffi"
+  assertCaptured "cffi"
+  assertCapturedSuccess
+}
+
+testPylibmc() {
+  compile "pylibmc"
+  assertCaptured "pylibmc"
+  assertCapturedSuccess
+}
+
 testPython2() {
   compile "python2"
   assertCaptured "python-2.7.13"
@@ -52,11 +67,30 @@ testPython2() {
 
 testPython3() {
   compile "python3"
-  assertCaptured "python-3.6.0"
+  assertCaptured "python-3.6.2"
   assertCapturedSuccess
 }
 
+testSmartRequirements() {
+  local cache_dir="$(mktmpdir)"
+  compile "requirements-standard" "$cache_dir"
+  assertFile "requests" ".heroku/python/requirements-declared.txt"
+  assertCapturedSuccess
+  compile "psycopg2" "$cache_dir"
+  assertCaptured "Uninstalling requests"
+  assertFile "psycopg2" ".heroku/python/requirements-declared.txt"
+  assertCapturedSuccess
+}
 
+testStackChange() {
+  local cache_dir="$(mktmpdir)"
+  mkdir -p "${cache_dir}/.heroku"
+  echo "different-stack" > "${cache_dir}/.heroku/python-stack"
+  compile "requirements-standard" "$cache_dir"
+  assertCaptured "clearing cache"
+  assertFile "$STACK" ".heroku/python-stack"
+  assertCapturedSuccess
+}
 
 
 pushd $(dirname 0) >/dev/null

test/utils

@@ -150,6 +150,11 @@ _assertContains()
     esac
 
     fail "${msg:-${default_msg}}"
+
+    if [ "${haystack_type}" == "file" ]; then
+      echo
+      cat "${haystack}"
+    fi
   fi
 }
 

vendor/WEB_CONCURRENCY.sh

@@ -5,25 +5,25 @@ case $(ulimit -u) in
 # Standard-1X (+Free, +Hobby) Dyno
 256)
   export DYNO_RAM=512
-  export WEB_CONCURRENCY=${WEB_CONCURRENCY:-02}
+  export WEB_CONCURRENCY=${WEB_CONCURRENCY:-2}
   ;;
 
 # Standard-2X Dyno
 512)
   export DYNO_RAM=1024
-  export WEB_CONCURRENCY=${WEB_CONCURRENCY:-04}
+  export WEB_CONCURRENCY=${WEB_CONCURRENCY:-4}
   ;;
 
 # Performance-M Dyno
 16384)
   export DYNO_RAM=2560
-  export WEB_CONCURRENCY=${WEB_CONCURRENCY:-08}
+  export WEB_CONCURRENCY=${WEB_CONCURRENCY:-8}
   ;;
 
 # Performance-L Dyno
 32768)
-  export DYNO_RAM=6656
-  export WEB_CONCURRENCY=${WEB_CONCURRENCY:-011}
+  export DYNO_RAM=14336
+  export WEB_CONCURRENCY=${WEB_CONCURRENCY:-11}
   ;;
 
-esac
+esac