Run gc.collect() twice in test_rename on Python 3.12#2109
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EliahKagan merged 1 commit intogitpython-developers:mainfrom Mar 9, 2026
Merged
Run gc.collect() twice in test_rename on Python 3.12#2109EliahKagan merged 1 commit intogitpython-developers:mainfrom
gc.collect() twice in test_rename on Python 3.12#2109EliahKagan merged 1 commit intogitpython-developers:mainfrom
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Recently, the conditional `gc.collect()` step for Python >= 3.12 in `TestSubmodule.test_rename` is often insufficient. This has mainly been seen in #2248. For example: https://github.com/gitpython-developers/GitPython/actions/runs/22864869684/job/66331124651?pr=2106#step:12:620 In principle, there can be situations with finalizers where a cycle is only collectable due to finalization that happened due to a previous collection. Therefore, there is occasionally a benefit to collecting twice. This does that, in the hope that it will help.
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Pull request overview
Improves test stability on Python 3.12+ (especially Windows) by increasing the likelihood that cyclic garbage with finalizers is fully collected before proceeding with submodule rename assertions.
Changes:
- Call
gc.collect()twice on Windows + Python 3.12+ inTestSubmodule.test_rename. - Add an inline note explaining why a second collection can help.
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EliahKagan
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Mar 9, 2026
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Mar 9, 2026
As discussed in gitpython-developers#2005 and gitpython-developers#2011, we had not been doing this before. Conditions have changed in two relevant ways: - The free-threaded interpreter has been around longer and it sees more use. - The macOS runners are very fast now. The specific motivations for doing this now are: - In view of the condition described in gitpython-developers#2109 and how the change there seems to have helped with it, there's some reason to think *patch* versions of Python sometimes affect GitPython in ways it makes possibly unfounded assumptions about the effect of garbage collection. This mainly affects Windows and it is not specific to free-threaded builds. However, in principle we could also see assumptions violated in tests we think always work on Unix-like operating systems, due to differences in how garbage collection works in free-threaded interpreters. Therefore, the assumption that this only needs to be tested occasionally is not as well founded I assumed when I suggested testing it only on GNU/Linux. - We may add 3.14 jobs to CI soon, and it's useful to be able to see how both free-threaded interpreters work on CI, as well as to confirm for at least a short while that they are continuing to work as expected. This macOS free-threaded interpreter CI jobs could be disabled once more if necessary, or if they're found to make CI complete slower in PRs by even a small amount so long as they don't seem to be surfacing anything.
EliahKagan
added a commit
to EliahKagan/GitPython
that referenced
this pull request
Mar 9, 2026
As discussed in gitpython-developers#2005 and gitpython-developers#2011, we had not been doing this before. Conditions have changed in two relevant ways: - The free-threaded interpreter has been around longer and it sees more use. - The macOS runners are very fast now. The specific motivations for doing this now are: - In view of the condition described in gitpython-developers#2109 and how the change there seems to have helped with it, there's some reason to think *patch* versions of Python sometimes affect GitPython in ways it makes possibly unfounded assumptions about the effect of garbage collection. This mainly affects Windows and it is not specific to free-threaded builds. However, in principle we could also see assumptions violated in tests we think always work on Unix-like operating systems, due to differences in how garbage collection works in free-threaded interpreters. Therefore, the assumption that this only needs to be tested occasionally is not as well founded I assumed when I suggested testing it only on GNU/Linux. - We may add 3.14 jobs to CI soon, and it's useful to be able to see how both free-threaded interpreters work on CI, as well as to confirm for at least a short while that they are continuing to work as expected. This macOS free-threaded interpreter CI jobs could be disabled once more if necessary, or if they're found to make CI complete slower in PRs by even a small amount so long as they don't seem to be surfacing anything.
EliahKagan
added a commit
to EliahKagan/GitPython
that referenced
this pull request
Mar 9, 2026
As discussed in gitpython-developers#2005 and gitpython-developers#2011, we had not been doing this before. Conditions have changed in two relevant ways: - The free-threaded interpreter has been around longer and it sees more use. - The macOS runners are very fast now. The specific motivations for doing this now are: - In view of the condition described in gitpython-developers#2109 and how the change there seems to have helped with it, there's some reason to think *patch* versions of Python sometimes affect GitPython in ways it makes possibly unfounded assumptions about the effect of garbage collection. This mainly affects Windows and it is not specific to free-threaded builds. However, in principle we could also see assumptions violated in tests we think always work on Unix-like operating systems, due to differences in how garbage collection works in free-threaded interpreters. Therefore, the assumption that this only needs to be tested occasionally is not as well founded I assumed when I suggested testing it only on GNU/Linux. - We may add 3.14 jobs to CI soon, and it's useful to be able to see how both free-threaded interpreters work on CI, as well as to confirm for at least a short while that they are continuing to work as expected. This macOS free-threaded interpreter CI jobs could be disabled once more if necessary, or if they're found to make CI complete slower in PRs by even a small amount so long as they don't seem to be surfacing anything.
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Recently, the conditional
gc.collect()step for Python >= 3.12 inTestSubmodule.test_renameis often insufficient. This has mainly been seen in #2248. For example:https://github.com/gitpython-developers/GitPython/actions/runs/22864869684/job/66331124651?pr=2106#step:12:620
In principle, there can be situations with finalizers where a cycle is only collectable due to finalization that happened due to a previous collection. Therefore, there is occasionally a benefit to collecting twice. This does that, in the hope that it will help.
As expanded on in my self-review comment below, I hope this is temporary, at least in this exact form.