Support Python 3.12 on Cygwin #1988
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Python 3.12 is currently marked "test" and should not be expected to fully work. Assuming this successfully installs it, based on local testing I expect two encounter two problems: 1. Currently, creating a venv with `pip` in Python 3.12 on Cygwin does not seem to be working, even though its own global `pip` exists. Running `python -m ensurepip` likewise does not work, reporting that the bundled `pip-24.3.1-py3-none-any.whl` does not exist. The https://bootstrap.pypa.io/get-pip.py script can be used as a workaround, assuming the problem also happens on CI (which I expect). Eventually, `pip` should be fully working. 2. Once that is worked around, there seem to be problems where Python processes terminate unexpectedly and wrongly report success, or where subprocess creation fails. When I ran `pytest` loading it as a module (`python -m pytest`), it collected tests and sometimes started running them, but then suddenly terminated with an exit status of 0. When I ran it via the `pytest` command (no `python -m`), that problem also usually happened, but one time I got an immediate termination instead, reporting the following errors, yet still with a 0 exit status: 0 [main] python3.12 2724 C:\cygwin64\bin\python3.12.exe: *** fatal error in forked process - WFSO timed out performed fork fixups and dynamic dll loading 0 [main] python3.12 2769 C:\cygwin64\bin\python3.12.exe: *** fatal error in forked process - WFSO timed out performed fork fixups and dynamic dll loading And one time I got an immediate termination reporting this slightly different error, also with an exit status of 0: 0 [main] python3.12 3371 C:\cygwin64\bin\python3.12.exe: *** fatal error in forked process - WFSO timed out after longjmp This curious combination of errors (or the same error arising and being reported in different ways?) is my main motivation for testing GitPython on CI with Python 3.12 in Cygwin now, even though the Cygwin package `python312` and assocated packages are still marked "test". If the problems I observed locally can be reproduced, then this may help to find a minimal case that shows the problem (assuming that it is due to a Cygwin-related bug). This commit contains no attempt to avoid or work around either of those two anticipated problems.
This works around a problem in Python 3.12 on Cygwin where `pip` fails to intall in a venv via `ensurepip` (both implicitly when the venv is created normally, and explicitly when `python -m ensurepip` is attempted), by creating the venv with `--without-pip` and then, once the venv is set up, bootstrapping `pip` in it by running the https://bootstrap.pypa.io/get-pip.py script. Eventually, when `pip` is working automatically in a venv in Python 3.12 on Cygwin (the problem is specific to that combination, and the Cygwin `python312*` packages are still marked "test"), this special-casing can be removed.
EliahKagan
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In both this older run before the #1989-related rebase, and this newer run, the Cygwin Python 3.12 job seems to stall either when attempting to download This resembles the problem described for Cygwin I have not reproduced that problem locally. The problems I encounter locally--other than the venv Edit: I also tried locally running the tests with an MSYS2 build of Python 3.12. (That is, with the downstream Python 3.12 packaged by the MSYS2 project for the MSYS environment. Other environments are native Windows builds, while the MSYS environment is Cygwin-like due to MSYS and MSYS2 being forked from Cygwin. In the MSYS2 build of Python, |
Cygwin has had Python 3.9 as its latest version for a while, with progress both on moving past 3.9.16 for Python 3.9, as well as on packaging Python 3.y for higher y, stalled due to the problem described in #1814. However, packaging work has resumed. This includes Cygwin builds of Python 3.12 (which is successfully packaged for the parallel/forked MSYS2 target). Such builds are marked "test" and do not work properly yet (reports and discussion can be seen in this month's list archive).
Since GitPython has long-standing support for Cygwin, which I suspect remains one of the important use cases of GitPython (with some alternatives not supporting Cygwin), it seems to me that it is worthwhile to support Python 3.12 on Cygwin, as well as to test it on CI. Since the Cygwin downstream build of Python 3.12 is currently experimental and not fully working, I don't expect GitPython to work with it yet. This PR is for testing that, and for keeping track of changes that are known to be wanted whenever Cygwin Python 3.12 is working. I have encountered substantial differences between CI and my local setup with Cygwin in the past, so testing this on CI now may help avoid surprises. It may also lead to the discovery of bugs, or information about known bugs, that could be useful to report on the Cygwin mailing list. This PR is definitely not ready to be merged.
This PR is separate from and in parallel to #1955 (which is about Python 3.13 and blocked due to a need to change some GitPython code to support that version on Windows), because they are conceptually separate with no known overlap in blockers or in changes that would fix them, and because it seems to me that having two PRs makes the situation clear, both to me and to other people who might wish to contribute.