Extremely slow start-up using `poetry run`

[daniel-soutar-ki]

Versions:
poetry: 2.1.1
Python 3.13.2
pytest 8.2.0
sortedcontainers 2.4.0 (from poetry run pip list)

In my current codebase I have recently had extremely slow start-up times with pytest.

Just running this command, for instance:

$ time poetry run pytest --version
pytest 8.2.0

real	0m32.409s
...

This looks somewhat familiar to #9941, in that it seems to get stuck around this line when running with PYTEST_DEBUG=1:

...
    early skip of rewriting module: sortedcontainers.sorteddict [assertion] # gets stuck here, next line doesn't print for ages
    early skip of rewriting module: MY_DIR.MY_DMODULE [assertion]  # this comes after, not sure if it's my code that's the culprit

Any idea why this should be so slow? The actual collection and running of tests is perfectly fine from what I can tell.

[daniel-soutar-ki]

I should add that even poetry run pthon --version isn't exactly fast (~5s), but this seems fast enough. 30+ seconds just getting the version for something is just silly.

[nicoddemus]

Hi @daniel-soutar-ki,

If you activate the environment first, it continues to be slow? If not the case, I think it might be an issue with poetry rather than pytest.

EDIT:

I should add that even poetry run pthon --version isn't exactly fast (~5s)

This should be instantaneous actually. If python --version is taking that long, definitely something fishy is going on.

[daniel-soutar-ki]

If I activate the environment first and run the commands:

$ poetry env activate
source /path/to/venv/.venv/bin/activate
$ source /path/to/venv/.venv/bin/activate 
(env-name-py3.13) $ time poetry run python --version
Python 3.13.2

real	0m1.075s
user	0m0.220s
sys	0m0.118s
(env-name-py3.13) $ time poetry run pytest --version
pytest 8.2.0

real	0m40.369s
user	0m25.273s
sys	0m4.308s
(env-name-py3.13) $ time .venv/bin/pytest --version  # Similarly slow with this command
pytest 8.2.0

real	0m30.851s
user	0m24.252s
sys	0m3.570s

So it seems poetry does something sensible with python, but pytest is still very slow.

[nicoddemus]

Thanks.

Could you try with the latest pytest version?