pylint not finding the tox.ini config

[rlalik]

Bug description

According to documentation: https://pylint.readthedocs.io/en/v3.2.3/user_guide/usage/run.html
pylint should be able to find tox.ini and use configuration from it.

In my case however it is not doing it. It works if I explicitely ask to use tox.ini with --rcfile.

Configuration

[tox]
env_list =
    py313
    py312
    py311
    py310
    py39
    py38
    type
    linter
    flake8

[testenv]
deps = -r {toxinidir}/requirements_test.txt
commands = pytest

[testenv:flake8]
deps = -r {toxinidir}/requirements_test.txt
commands = flake8

[flake8]
exclude = .tox,tests
max-line-length = 120


[testenv:type]
deps = -r {toxinidir}/requirements_test.txt
commands = mypy --ignore-missing-imports .

[testenv:pylint]
deps = pylint
commands = pylint *.py

[pylint]
disable = C0114,C0115,C0116

Command used

pylint fraction.py -v

Pylint output

No config file found, using default configuration
************* Module fraction
fraction.py:1:0: C0114: Missing module docstring (missing-module-docstring)
fraction.py:4:0: C0115: Missing class docstring (missing-class-docstring)
fraction.py:63:4: C0116: Missing function or method docstring (missing-function-docstring)
fraction.py:66:4: C0116: Missing function or method docstring (missing-function-docstring)

---------------------------------------------------------------------------------------------------
Your code has been rated at 9.02/10 (previous run: 9.02/10, +0.00)
Checked 1 files, skipped 1 files

Expected behavior

Same as using with --rcfile:

$ pylint fraction.py -v --rcfile=tox.ini
Using config file tox.ini

----------------------------------------------------------------------------------------------------
Your code has been rated at 10.00/10 (previous run: 9.02/10, +0.98)
Checked 1 files, skipped 1 files

Pylint version

pylint 3.2.3
astroid 3.2.2
Python 3.12.3 (main, May 22 2024, 16:56:59) [GCC 13.3.0]

OS / Environment

Gentoo

Additional dependencies

No response

[mbyrnepr2]

Hi! I don’t know for certain what is going on but the docs also say that without the rcfile option, Pylint will use the first configuration file it can find, based on a specific order mentioned in same doc page.
So, do you also have, for example, a pyproject.toml file in the current directory which is getting picked up instead of the tox.ini because of the precedence?
Edit: just noticed the message says no config is found😅

[mbyrnepr2]

Need to verify when not on mobile but it could be because the config needs to be [pylint.main]

[rlalik]

I've checked options 1-5 from doc by putting dummy files and the config file is detected properly. I skipped setup.cfg. In my project there are no files from 1-6 which could be read before. If there was, the pylint would display it like this:

$ touch .pylintrc
$ pylint -v fraction
Using config file (...)/.pylintrc

So I assume it is not able to detect tox.ini.

Also, I tried [pylint] and [pylint.main]. According to

pylint/pylint/config/config_file_parser.py

Line 46 in 2ba88b9

if ini_file_with_sections and not section.startswith("pylint"):

it looks for anything starting with pylint. I also tried with dummy setup.cfg where I just copied tox.ini as setup.cfg and the result was the same.

[mbyrnepr2]

Thanks @rlalik for the details. Makes perfect sense and I see what is missing from the code now. PR coming.

[rlalik]

I think you still might have issuie with setup.cfg:

$ cp tox.ini setup.cfg
$ pylint fraction.py -v
No config file found, using default configuration
$ pylint fraction.py -v --rcfile=setup.cfg 
Using config file setup.cfg

By looking at your PR it seems that is not fixing it.

[mbyrnepr2]

I think you still might have issuie with setup.cfg:

$ cp tox.ini setup.cfg
$ pylint fraction.py -v
No config file found, using default configuration
$ pylint fraction.py -v --rcfile=setup.cfg 
Using config file setup.cfg

By looking at your PR it seems that is not fixing it.

I can't reproduce that unfortunately. Does your tox.ini have a valid configuration section ([pylint])?

[rlalik]

$ cp tox.ini setup.cfg
$ grep "\[pylint\]" setup.cfg -A 5
37:[pylint]
38-disable = C0114,C0115,C0116
39-

$ pylint fraction.py -v
No config file found, using default configuration

So unless setup.cfg must be a valid setuptools file, if it is only required to have [pylint] then it is not working.

[mbyrnepr2]

I see the problem - .cfg and .ini config files' config need to begin with pylint. (note the dot and that's also mentioned in the documentation). So something like [pylint.main] is expected there; I can reproduce your issue with [pylint] but not [pylint.main].

[rlalik]

So, is it something else than in this line:

pylint/pylint/config/config_file_parser.py

Line 46 in 2ba88b9

if ini_file_with_sections and not section.startswith("pylint"):

?

[rlalik]

And it works with [pylint] and --rcfile for both tox.ini and setup.cfg. So there must be some other issue about autodetection?

[rlalik]

And it says the same for e.g. pylintrc.toml but works without dot as well:

$ cat pylintrc.toml 
[tool.pylint]
disable = ["C0114", "C0115", "C0116"]

$ pylint fraction.py -v
Using config file (...)/pylintrc.toml

[mbyrnepr2]

Thanks again @rlalik. Good feedback.
If you have time please check out the new changes and see if it hits the right notes 👍