Add more misspellings to the .python-version filename check (#2051)

Based on misspellings seen in Honeycomb, that affected more than
one app.

Having this fixed list of misspellings isn't ideal (given there will be a long
tail of misspellings not on it), however, short term it allows us to offer
a very specific error message so the majority of apps are fixed by their
owners, whilst still maintaining a low false positive rate (vs a looser regex).

Longer term we'll likely be making the `.python-version` file mandatory,
at which point the error message for that can list out the files in the app
source root (the same way we do for detection errors), which will help
with the long tail cases. (We can also do things like replace unicode or
stray whitespace in the file listing, to make those confusing for the user
cases easier to spot too.)

GUS-W-21320154.

Author: edmorley

CHANGELOG.md

@@ -4,6 +4,7 @@
 
 - Updated uv from 0.10.7 to 0.10.9. ([#2049](https://github.com/heroku/heroku-buildpack-python/pull/2049))
 - Switched to downloading uv from `releases.astral.sh` instead of GitHub releases. ([#2050](https://github.com/heroku/heroku-buildpack-python/pull/2050))
+- Updated the check for misspelled `.python-version` files with additional misspellings seen in the wild. ([#2051](https://github.com/heroku/heroku-buildpack-python/pull/2051))
 
 ## [v338] - 2026-03-03
 

lib/python_version.sh

@@ -25,9 +25,12 @@ PYTHON_FULL_VERSION_REGEX="${INT_REGEX}\.${INT_REGEX}\.${INT_REGEX}"
 
 # Misspellings of the `.python-version` file seen in the wild.
 MISSPELLED_PYTHON_VERSION_FILE_NAMES=(
+	" .python-version"
+	". python-version"
 	".python_version.txt"
 	".python_version"
 	".python-version "
+	",python-version"
 	".python-version."
 	".python-version.py"
 	".python-version.rtf"