Python 3.15: os.path.commonprefix() deprecated in norm_and_check

[gaborbernat]

Python 3.15 deprecated os.path.commonprefix() (cpython#74453). pyproject_hooks/_impl.py:120 uses it in norm_and_check():

if os.path.commonprefix([norm_source, norm_requested]) != norm_source:

On Python 3.15, this raises a DeprecationWarning. For any project running tests with filterwarnings = "error", this causes test failures:

E       DeprecationWarning: os.path.commonprefix() is deprecated. Use os.path.commonpath() for longest path prefix.

pyproject_hooks/_impl.py:120: DeprecationWarning

Note the code comment says "We have to use commonprefix for Python 2.7 compatibility" — Python 2.7 is long EOL so this can be replaced. However os.path.commonpath() is not a drop-in replacement (different semantics). A simple string comparison would work here since norm_source is already normalized:

if not abs_requested.startswith(abs_source):

Environment: Python 3.15.0a6, pyproject-hooks 1.2.0

[takluyver]

I think commonpath is actually what we want here, or norm_requested.startswith(norm_source + os.sep). There's a minor bug in the current implementation using commonprefix.

[notatallshaw]

See also #222 and #221

[takluyver]

Oops, thanks, I had missed those.

[takluyver]

Fixed by #222