Correctly handle tilde directories in site-packages

[bersbersbers]

pip version

21.0.1

Python version

3.8.5

OS

Windows 10

Additional information

No response

Description

From time to time, I get folder situations like this in my site-packages folder (C:\Programs\Python\Python38\Lib\site-packages), see image below. This generates all kinds of problems, such as

C:\>pip list --format=freeze
-ffi==1.14.4
2to3==1.0
absl-py==0.11.0
...

C:\>pip freeze
WARNING: Could not generate requirement for distribution -ffi 1.14.4 (c:\users\bers\appdata\local\programs\python\python38\lib\site-packages): Parse error at "'-ffi==1.'": Expected W:(abcd...)
2to3==1.0
absl-py==0.11.0

Expected behavior

I am not sure. Probably, pip should at least ignore these directories. Possibly delete them. Maybe never even create them.

How to Reproduce

I don't know. I think it happens when package (here: cffi, I guess) upgrades fail (sometimes they do due to permissions, which may be due other still-running python processes), but I cannot easily reproduce.

Output

No response

Code of Conduct

• I agree to follow the PSF Code of Conduct

[uranusjr]

#7269.

BTW the character - is a dash, not a tilde (~).

[bersbersbers]

#7269.

Thanks!

BTW the character - is a dash, not a tilde (~).

That's correct. The character used in the file system is a tilde, however (see also my first screenshot):

pip/src/pip/_internal/utils/temp_dir.py

Line 203 in 4b5b151

# We always prepend a ~ and then rotate through these until

pip/src/pip/_internal/utils/temp_dir.py

Line 228 in 4b5b151

new_name = "~" + "".join(candidate) + name[i:]

[uranusjr]

Looks like the pip freeze output becomes a dash due to some pkg_resources quirks. Thanks for digging into the details for this!