From 64abfb297805a70c5eb44284e47ff1a89f44465c Mon Sep 17 00:00:00 2001
From: Ed Morley <501702+edmorley@users.noreply.github.com>
Date: Wed, 16 Sep 2020 12:28:15 +0100
Subject: [PATCH] Emit Python version metric events for all builds (#1066)

Previously the metric events describing the chosen Python version were
only emitted when that Python version was installed, and not when it
was being used from the build cache (the common case).

Now the version is emitted for all builds, improving visibility into
the distribution of Python usage, and helping determine the priority
of features like opt-in automatic Python patch updates.

Closes @W-8059668@.
---
 CHANGELOG.md     | 1 +
 bin/steps/python | 4 ++--
 2 files changed, 3 insertions(+), 2 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index e55587f..9bdbb09 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,6 +2,7 @@
 
 ## Unreleased
 
+- Emit Python version metric events for all builds, not just clean installs (#1066).
 
 ## v178 (2020-09-07)
 
diff --git a/bin/steps/python b/bin/steps/python
index c4804bd..131c293 100755
--- a/bin/steps/python
+++ b/bin/steps/python
@@ -80,6 +80,8 @@ else
   exit 1
 fi
 
+mcount "version.python.${PYTHON_VERSION}"
+
 if [[ "$STACK" != "$CACHED_PYTHON_STACK" ]]; then
     puts-step "Stack has changed from $CACHED_PYTHON_STACK to $STACK, clearing cache"
     rm -fr .heroku/python-stack .heroku/python-version .heroku/python .heroku/vendor .heroku/python .heroku/python-sqlite3-version
@@ -119,8 +121,6 @@ if [ ! "$SKIP_INSTALL" ]; then
     # Prepare destination directory.
     mkdir -p .heroku/python
 
-    mcount "version.python.$PYTHON_VERSION"
-
     if ! curl "${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"