Bug report

Bug description:

Good evening,

I have recently installed Python 3.13 (Windows x64) over 3.12.
Nowzipapp.create_archive(..) is creating just empty archives.

After some fiddling around I found there might be an issue in these lines:

(from zipapp.py, lines 113 ff)

    with _maybe_open(target, 'wb') as fd:        _write_file_prefix(fd, interpreter)        compression = (zipfile.ZIP_DEFLATED if compressed else                       zipfile.ZIP_STORED)        with zipfile.ZipFile(fd, 'w', compression=compression) as z:            for child in sorted(source.rglob('*')):                arcname = child.relative_to(source)                if filter is None or filter(arcname) and child.resolve() != arcname.resolve():   # ██ LOOK HERE ! ██                    z.write(child, arcname.as_posix())            if main_py:                z.writestr('__main__.py', main_py.encode('utf-8'))

This change was introduced in Python 3.13 (have verified against 3.12 sources) and seemingly causes the trouble.

My guess is, aschild is pointing to the same file asarcname, and naturally, they both resolve to the same file, no file gets added due to the!= check, ever, to the archive-to-be-created.

Maybe it was intended to check againsttarget, notarcname?

Once I monkeypatched theand child.resolve() != arcname.resolve() part away, the archive got written again.

Or am I just not doing it right?
Any help much appreciated!

Sebastian.

CPython versions tested on:

3.13

Operating systems tested on:

Windows

Linked PRs

• gh-130379: Fix incorrect zipapp logic to avoid including the target in itself #130509
• [3.13] gh-130379: Fix incorrect zipapp logic to avoid including the target in itself (gh-130509) #130791