Vendoring process fails on Windows

Environment

• pip version: master
• Python version: 3.8
• OS: Windows 10

Description

Running tox -e vendoring fails on Windows.

The reason for the failure seems to be newline normalization – see https://github.com/pypa/pip/commit/5563141d58bc17d5fab3bf4ca1649e136e25696c/checks/396942169/logs (from #7611). The patching process failed and vendoring (the tool) did not error out immediately. The git diff --exit-code catches the problem though. 😃

Expected behavior

tox -e vendoring should work on all platforms.

How to Reproduce

1. Checkout pip’s current master on Windows.
2. Run tox -e vendoring
3. An error occurs.

Output

From the logs linked above, the relevant lines are:

2020-01-18T18:29:27.6652039Z   Running git apply --verbose 'tools\automation\vendoring\patches\requests.patch'
2020-01-18T18:29:27.6652131Z     error: corrupt patch at line 7

[pfmoore]

I’d prefer to go with native line endings, as that’s less likely to have odd side-effects (even though most editors work fine with \n line endings, they typically default to \r\n for new files).

Treating patch files as special makes more sense to me, because, well, they are - the patch utilities are what don’t handle mixed line endings cleanly.

Actually, it looks like the problem is far simpler than all this - when we moved the patches from tasks to tools/automation, the .gitattributes file wasn’t updated! I’ve just filed #7641 to fix this - it works on my PC, but if anyone else can test it as well, that would be great (I may not wait for confirmation from others before merging - it’s the right change to make regardless).

[pradyunsg]

Yup!