Fix activation paths in cygwin using cygpath

[danyeaw]

This PR fixes #1969. It removes use of a regex to transform the path when using cygwin or MSYS2 and instead makes use of the cygpath utility.

@davidcoghlan would you be able to test in cygwin please?

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[codecov]

Codecov Report

Merging #1973 into main will increase coverage by 2.25%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##             main    #1973      +/-   ##
==========================================
+ Coverage   87.45%   89.70%   +2.25%     
==========================================
  Files         174       87      -87     
  Lines        8496     4245    -4251     
==========================================
- Hits         7430     3808    -3622     
+ Misses       1066      437     -629     

Flag	Coverage Δ
#tests	89.70% <ø> (+2.25%)	⬆️

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Impacted Files	Coverage Δ
...nv/create/via_global_ref/builtin/cpython/mac_os.py
src/virtualenv/app_data/na.py
src/virtualenv/config/ini.py
src/virtualenv/discovery/discover.py
src/virtualenv/util/zipapp.py
src/virtualenv/create/via_global_ref/store.py
src/virtualenv/app_data/base.py
src/virtualenv/discovery/__init__.py
src/virtualenv/run/plugin/activators.py
...ualenv/seed/embed/via_app_data/pip_install/base.py
... and 78 more

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[gaborbernat]

You'll need to fix the CI

[gaborbernat]

can you move this variable inline, and make it a tuple? 😊 And end it with a coma to have each name on it's own line to make it merge friendly? Thanks!

[gaborbernat]

Also use _ and __ for the variable names you don't need/use; though you should raise here in error if the code is not zero, not? with the out and error attached to the error

[gaborbernat]

Per #1970 (comment) the regex we have works fine, the issue is different so we can save the subprocess call for now.

[davidcoghlan]

Hi @gaborbernat @danyeaw, there are two issues here I think:

1. The regex maps paths of the form c:\somePath to /c/somePath -- this isn't right for Cygwin, it should be /c/cygdrive/somePath.
2. If people are using the regular Windows Python build, rather than a Cygwin-specific build, the platform type is reported as win-amd64, so we don't even hit this code path.

We are in group (2) unfortunately, so it's actually a bit difficult for me to test the change you made on this PR. I've tried installing some of the Cygwin Python packages, but it always seems to pick the main Windows Python interpreter when I run virtualenv, and I'm not too sure how to make it pick the Cygwin one.

The change looks good to me though! I suspect you will need something like this to support other Cygwin folks, even if it doesn't work for us due to the second issue.