Capital letter in directory name causes pip editable install to fail in Windows

Description

In Windows when the directory name of a Python project, such as a just cloned Git repository, contains a capital letter, installing it with -e (for editable) will result in a “Succesfullly installed”-message, but it actually failed: in pip list the package is nowhere to be found. In macOS I’m not having this issue.

With capital letter in directory name

Note that it reported Successfully installed example but without version number.

All lowercase letters

Expected behavior

No response

pip version

21.1.2

Python version

3.8.10

OS

Windows 10 21.1.2

How to Reproduce

I createda simple repo to reproduce the above example, but you can try it with any other repository as well.

git clone https://github.com/sandertan/Example
cd Example
pip install -e .

As mentioned previously, this only occurs in Windows and not on macOS. I’m using Bash that came with Git, and I also experienced this bug with the default Windows Shell.

Output

No response

Code of Conduct

• I agree to follow the PSF Code of Conduct.

[pfmoore]

This doesn’t happen for me:

PS 20:20 (test1) 00:00.038 C:\Work\Scratch\ex
❯ pip list
Package    Version
---------- -------
pip        21.1.2
setuptools 57.0.0
wheel      0.36.2
PS 20:21 (test1) 00:02.552 C:\Work\Scratch\ex
❯ git clone https://github.com/sandertan/Example
Cloning into 'Example'...
remote: Enumerating objects: 6, done.
remote: Counting objects: 100% (6/6), done.
remote: Compressing objects: 100% (4/4), done.
remote: Total 6 (delta 0), reused 6 (delta 0), pack-reused 0
Receiving objects: 100% (6/6), done.
PS 20:22 (test1) 00:01.304 C:\Work\Scratch\ex
❯ cd .\Example\
PS 20:22 (test1) [Git: main] 00:00.027 C:\Work\Scratch\ex\Example
❯ pip install -e .
Obtaining file:///C:/Work/Scratch/ex/Example
Collecting PyYAML
  Using cached PyYAML-5.4.1-cp39-cp39-win_amd64.whl (213 kB)
Installing collected packages: PyYAML, example
  Running setup.py develop for example
Successfully installed PyYAML-5.4.1 example-0.1.0
PS 20:22 (test1) [Git: main] 00:01.944 C:\Work\Scratch\ex\Example
❯ pip list
Package    Version Location
---------- ------- --------------------------
example    0.1.0   c:\work\scratch\ex\example
pip        21.1.2
PyYAML     5.4.1
setuptools 57.0.0
wheel      0.36.2

Could you do dir %VIRTUAL_ENV%\Lib\site-packages? I’d expect to see an easy-install.pth in there with the location of your example project in it, and an example.egg-link file with the Example directory path in it and a line containing “.”

[pfmoore]

This looks like it might be a mingw64 copy of Python, which is fairly heavily patched. Can you reproduce this issue with the standard python.org (or Windows Store) distribution of Python? If you can’t, I’d suggest that you may need to take this up with the mingw project, as it’s likely their port that’s the issue.