Filtering outdated packages does nothing.

[AWolters-ru]

Environment

• pip version: 18.1
• Python version: 3.6.0
• OS: Windows 10, Version 1803

Description
When running pip list --outdated or pip list --uptodate, the programm just freezes for what seems to be ever and does not give any output. Same thing with python -m pip, too.

Expected behavior
Either a list of the outdated or of the not outdated packages(depending on the option) should be printed to the console.

How to Reproduce
Just run one of the commands above.

Output
pip list --oudated
At least 30 minutes of nothing
(In red:) Operation cancelled by user.

[squaresmile]

I also experienced this problem. Here is the verbose log:

1 location(s) to search for versions of ipython:
* https://pypi.org/simple/ipython/
Getting page https://pypi.org/simple/ipython/
Looking up "https://pypi.org/simple/ipython/" in the cache
Request header has "max_age" as 0, cache bypassed
https://pypi.org:443 "GET /simple/ipython/ HTTP/1.1" 200 21972
Updating cache with response from "https://pypi.org/simple/ipython/"
Caching due to etag
Exception information:
Traceback (most recent call last):
  File "c:\users\squaresmile\appdata\local\programs\python\python37\lib\site-packages\pip\_vendor\lockfile\mkdirlockfile.py", line 40, in acquire
    os.mkdir(self.lock_file)
FileExistsError: [WinError 183] Cannot create a file when that file already exists: 'c:\\users\\squaresmile\\appdata\\local\\pip\\cache\\http\\c\\a\\4\\0\\5\\ca40521d6f4ca2bc510659d13a3cff56d7241103db5d1e645bc10f8f.lock'

Removing the cache file fixed it. I don't know why it's there in the first place.

[chrahunt]

This looks like it may be a duplicate of #3532.

[pradyunsg]

Sounds right to me. I'll close this eagerly -- if what @chrahunt said doesn't look right, please leave a comment.