_build: fix dynamic version when building from sdist

[FFY00]

Signed-off-by: Filipe Laíns lains@riseup.net

[henryiii]

Usually this means there's a missing close somewhere, say a file opened without a context manager, etc. Only Windows cares about files being closed before deletion, so it only shows up on Windows.

[henryiii]

In trampolim/_sdist.py, there are two manual calls to .close() without context managers. Context managers should be used, or they should be in a try:/finally: block. The files might not be closed if an error is thrown.

[FFY00]

That makes the code slightly harder to read, as it introduces two indentation levels. However, we are not handling the closing in case of an exception, so we can use https://docs.python.org/3/library/contextlib.html#contextlib.closing to fix that.

[henryiii]

You can use contextlib.ExitStack to avoid nested exceptions, like I did in #21 (though I didn't realize that the source context manager didn't cover the whole function, so it does need one extra indentation level).

You don't need to wrap tar file.TarFile in a closing context manager, it already has one since Python 3.2. GzipFile does seem to be missing a context manager, so it does a closing wrapper.

[henryiii]

This try/except needs to be reverted to the version on main. It's hiding potential valid errors.

[henryiii]

Why is 3.10 passing?

[henryiii]

Session test-3.10 skipped: Python interpreter 3.10 not found.

Oh. That's why.

[FFY00]

Yup. If you want to fix that...

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I don't know where the issue is, it errors out as

PermissionError: [WinError 32] The process cannot access the file because it is being used by another process: 'C:\\Users\\RUNNER~1\\AppData\\Local\\Temp\\trampolim-test-s_oya_bn\\no-version-1.0.0+custom'

Which is a directory. I don't have time to track it down right now, so this will have to be on hold for a little while.

[henryiii]

I'll try to turn on my Windows box and see if I can debug locally soonish.

[FFY00]

Thank you 🙏

[henryiii]

LGTM!