remark: issue on my big requirement.txt file when pip-master-2021_11_28

[stonebig]

Description

I installed pip from master of today, on Python-3.9.9. (9cf35b2)

it was to try out the speed-up by Simplify graph in get_topological_weights.

installing then my big requirement, I get this strange message (after it has handled a big list of wheels):

ERROR: Exception:
Traceback (most recent call last):
  File "C:\WinP\bd39\bu\WPy64-3990b1\python-3.9.9.amd64\lib\site-packages\pip\_internal\cli\base_command.py", line 165, in exc_logging_wrapper
    status = run_func(*args)
  File "C:\WinP\bd39\bu\WPy64-3990b1\python-3.9.9.amd64\lib\site-packages\pip\_internal\cli\req_command.py", line 205, in wrapper
    return func(self, options, args)
  File "C:\WinP\bd39\bu\WPy64-3990b1\python-3.9.9.amd64\lib\site-packages\pip\_internal\commands\install.py", line 388, in run
    to_install = resolver.get_installation_order(requirement_set)
  File "C:\WinP\bd39\bu\WPy64-3990b1\python-3.9.9.amd64\lib\site-packages\pip\_internal\resolution\resolvelib\resolver.py", line 186, in get_installation_order
    weights = get_topological_weights(
  File "C:\WinP\bd39\bu\WPy64-3990b1\python-3.9.9.amd64\lib\site-packages\pip\_internal\resolution\resolvelib\resolver.py", line 274, in get_topological_weights
    assert len(weights) == expected_node_count
AssertionError

Expected behavior

no error

pip version

22.0.dev0

Python version

3.9.9

OS

Windows 10

How to Reproduce

install Python-3.9.9 64 bit on Windows 10 and latest Pip-master of 2021-11-28
then install a big requirement file

pip install --pre  --no-index --trusted-host=None  --find-links=C:\WinP\packages.srcreq -c C:\WinP\constraints.txt -r   Qt5_requirements64.txt

Output

pip install --pre  --no-index --trusted-host=None  --find-links=C:\WinP\packages.srcreq -c C:\WinP\constraints.txt -r C:\WinP\bd39\Qt5_requirements64.txt

gives

ERROR: Exception:
Traceback (most recent call last):
  File "C:\WinP\bd39\bu\WPy64-3990b1\python-3.9.9.amd64\lib\site-packages\pip\_internal\cli\base_command.py", line 165, in exc_logging_wrapper
    status = run_func(*args)
  File "C:\WinP\bd39\bu\WPy64-3990b1\python-3.9.9.amd64\lib\site-packages\pip\_internal\cli\req_command.py", line 205, in wrapper
    return func(self, options, args)
  File "C:\WinP\bd39\bu\WPy64-3990b1\python-3.9.9.amd64\lib\site-packages\pip\_internal\commands\install.py", line 388, in run
    to_install = resolver.get_installation_order(requirement_set)
  File "C:\WinP\bd39\bu\WPy64-3990b1\python-3.9.9.amd64\lib\site-packages\pip\_internal\resolution\resolvelib\resolver.py", line 186, in get_installation_order
    weights = get_topological_weights(
  File "C:\WinP\bd39\bu\WPy64-3990b1\python-3.9.9.amd64\lib\site-packages\pip\_internal\resolution\resolvelib\resolver.py", line 274, in get_topological_weights
    assert len(weights) == expected_node_count
AssertionError

Code of Conduct

• I agree to follow the PSF Code of Conduct.

[stonebig]

... going to retry exact same scenario with normal pip-21.3.1

[pradyunsg]

Hiya!

You’re going to need to share a proper reproducer for this issue. As it stands, there’s absolutely nothing here that I can go on to even attempt to figure out what’s wrong beyond a general region of the codebase.

Please share a requirements.txt file and detailed steps on how to use that to recreate the issue you’re seeing.

[stonebig]

the remark is because I suspected the problem arrived with recent comits.
I confirm it doesn't happen per just switching back to "pip-21.3.1" and doing the same steps

requirement file:
Qt5_requirements64.txt

results when it works:
build_3.9._.0_b1_of_28-11-2021_at_13_39.txt.packages_versions.txt

constraint file (in case it contributes to the problem):

constraints.txt

at the moment, it's just an input, I don't expect you can reproduce this too particular big example.

[pradyunsg]

This issue has since been fixed: #10851