Fix: Addon Manager Python dependency update detection in Flatpak

[omkarrr2533]

Problem Description

Fixes FreeCAD/FreeCAD#26510

When updating Python dependencies through the Addon Manager in Flatpak installations, the update process completes successfully but FreeCAD continues to show the old version as available for update. This occurs because:

1. pip installs the new package version to the target directory (~/.var/app/org.freecad.FreeCAD/data/FreeCAD/AdditionalPythonPackages/py312)
2. The old package version's .dist-info metadata directory remains in place
3. FreeCAD's version detection scans the directory and finds the old version first, stopping its search

This causes users to repeatedly see the same updates available even after successful installation.

Solution

This PR adds a _cleanup_old_package_versions() method that runs after package updates complete. The method:

• Scans the pip target directory for all .dist-info directories
• Groups them by package name (normalized per PEP 503)
• For packages with multiple versions, removes all but the newest version's metadata
• Logs cleanup actions for debugging

The cleanup only runs for non-system pip installations (like Flatpak), where the --target directory is used and multiple versions can accumulate.

Changes Made

• Modified update_call_finished() in addonmanager_python_deps.py to call cleanup after update completes
• Added new _cleanup_old_package_versions() method to handle old version removal
• Uses existing Version class for accurate version comparison
• Includes proper error handling to prevent cleanup failures from breaking updates

Testing

The fix has been tested by:

• Verifying the cleanup logic correctly identifies and removes old .dist-info directories
• Ensuring the newest version is preserved after cleanup
• Confirming error handling prevents crashes if cleanup fails

Manual testing in a Flatpak environment would be appreciated to confirm the fix resolves the reported issue.

Additional Notes

This fix is specifically targeted at Flatpak and similar installations where using_system_pip_installation_location() returns False. Regular system installations and virtual environments are not affected as they already handle package updates correctly through pip's standard mechanisms.

Fixes #26510

[omkarrr2533]

Hi @chennes,

I'm a new contributor working on fixing issue #26510 (Python dependency updates in Flatpak). Would you be able to review this PR when you have a chance? I'd really appreciate any feedback or suggestions for improvement.

Thank you for your time and for maintaining this project!

[chennes]

Hello @omkarrr2533 -- thanks for your work on this bug. I am happy to review your PR. It will probably take me a couple of days before I can get to it. Thanks for your patience!

[omkarrr2533]

Thanks @chennes! Really appreciate you taking a look. Whenever you get to it is totally fine - no rush!

Looking forward to your feedback!

[chennes]

@omkarrr2533 can you add some tests of _cleanup_old_package_versions to test_python_deps.py? Let me know if you need help with the mocks.

[omkarrr2533]

thanks @chennes! i'll work on adding test for _cleanup_old_package_versions() to test_python_deps.py

I am planning to test like:
*multiple package versions (keep newest, remove old)
*single version (no cleanup needed)
*Empty directory handling
*error handling for permission issues.

if i get stuck with the mocks, i'll definitely reach out. thanks for offering to help!

[chennes]

Thanks for adding the tests -- overall they look good. One small comment below, and also I suspect that theses tests won't work on Windows since they are using a hardcoded path separator, but internally the code is using os.path.join -- I'd guess your strings won't match. Do you have access to a Windows system to test on?

[chennes]

I probably wouldn't test this: we don't really want to have to update the tests just because we change the logging.

[omkarrr2533]

thanks @chennes I've addressed both the points

• Removed the logging assertion you're right I shouldn't test implementation details
• fixed windows compatibility - replaced all hardcoded paths with 'os.path.join()'

Unfortunately I don't have access to a Windows system to test on, but the changes should now work correctly since we're using the same os.path.join() approach as the main code.