test_install_from_wheel_with_headers appears to be flaky, I was able to reproduce the failure locally initially, but on rerun I can no longer reproduce it.

Looks good :)

test_install_from_wheel_with_headers appears to be flaky, I was able to reproduce the failure locally initially, but on rerun I can no longer reproduce it.

This fails consistently in CI, but inconsistently locally 🙁, I will investigate.

@notatallshaw it fails consistently locally for me. I copied the old Wheel class, creating both the new and old classes to compare the final attributes. It looks like the packaging-based implementation is normalizing the wheel name hence the FileNotFoundError.

self.name='headers-dist', self.version='0.1', self.build_tag=(), self.file_tags=frozenset({<py3-none-any @ 139308783286464>, <py2-none-any @ 139308783286976>})
old_whl.name='headers.dist', old_whl.version='0.1', old_whl.build_tag=None, old_whl.file_tags={<py3-none-any @ 139308783287168>, <py2-none-any @ 139308783286848>}

The headers are placed in a directory with the normalized name (although the dist-info is still not normalized...)

diff --git a/tests/functional/test_install_wheel.py b/tests/functional/test_install_wheel.py
index 7e7aeaf7a..e01ecfb57 100644
--- a/tests/functional/test_install_wheel.py
+++ b/tests/functional/test_install_wheel.py
@@ -190,7 +190,7 @@ def test_install_from_wheel_with_headers(script: PipTestEnvironment) -> None:
     dist_info_folder = script.site_packages / "headers.dist-0.1.dist-info"
     result.did_create(dist_info_folder)
 
-    header_scheme_path = get_header_scheme_path_for_script(script, "headers.dist")
+    header_scheme_path = get_header_scheme_path_for_script(script, "headers-dist")
     header_path = header_scheme_path / "header.h"
     assert header_path.read_text() == header_text

Historically, tools have failed to replace dot characters or normalize case in the name field, or not perform normalization in the version field. Tools consuming .dist-info directories should expect those fields to be unnormalized, and treat them as equivalent to their normalized counterparts. New tools that write .dist-info directories MUST normalize both name and version fields using the rules described above, and existing tools are encouraged to start normalizing those fields.

https://packaging.python.org/en/latest/specifications/recording-installed-packages/#the-dist-info-directory

Ah, that checks out. Heh.

This is ready for review and merge.

Holding off on merging this until the discussion in pypa/packaging#873 has concluded, may end up pushing this to a later pip release.

I've found a real world examples where this PR would currently throw an error but there is no deprecation warning:

$ pip install "en_core_web_sm @ https://huggingface.co/spacy/en_core_web_sm/resolve/main/en_core_web_sm-any-py3-none-any.whl"
ERROR: Invalid wheel filename (invalid version): 'en_core_web_sm-any-py3-none-any

I don't think this is a supported use case, but I don't want to surprise users, so I plan to do the following in a new PR:

1. Initially parse with parse_wheel_filename
2. If fails fall back to old regex
   a. If succeed with old regex throw deprecation warning
   b. If fail with old regex throw with message from parse_wheel_filename

The new deprecation warning will be for it to be gone in pip 25.3.