Pin to pip 9.0.2 for pipenv users only

Claudio Jolowicz · Claudio Jolowicz · commit 8408e3463967 · 2019-10-03T17:14:46.000+02:00
This addresses an issue raised by @CaseyFeist during code review: Updating pip for pipenv users or requiring them to update without a heads up won't be a good experience (our version is old enough that they'll need to uninstall and reinstall pipenv locally to successfully update). If you can refactor this to stay pinned to current version for pipenv users only, I should be able to accept this (and the related project updates). #833 (comment)
diff --git a/bin/compile b/bin/compile
@@ -74,6 +74,11 @@ for file in "$BUILD_DIR/runtime.txt" "$CACHE_DIR/.heroku/python-version" ; do
     esac
 done
 
+if [[ -f "$BUILD_DIR/Pipfile" ]]; then
+    # Do not force pipenv users to re-install pipenv locally.
+    PIP_UPDATE="9.0.2"
+fi
+
 export DEFAULT_PYTHON_STACK PIP_UPDATE
 export PY37 PY36 PY35 PY27 PY34
 
