python-ruff problem with ignore-per-file extensions

[twmr]

Checklist

• I have checked existing issues for potential duplicates before creating this one.
• I have read the Troubleshooting guide.

Bug description

When the python-ruff checker is used in a buffer for which special ignore-rules apply (can be set via e.g. [lint.extend-per-file-ignores] in ruff.toml), these ignore-rules are not considered.

It seems as if this is due to the value of default-directory, which is used for running ruff.
When I run flycheck-compile on a python file in mypkg/ in my project, it shows that

ruff check --config /tmp/ruff-example/ruff.toml --output-format\=text --stdin-filename /tmp/ruff-example/mypkg/mymod.py - < /tmp/ruff-example/mypkg/mymod.py

is called in /tmp/ruff-example/mypkg.

My ruff.toml file exists in the project root: /tmp/ruff-example.

Since ruff is not called in the project-root, my special ignore extensions:

[lint.extend-per-file-ignores]
"__init__.py" = ["E402", "D104"]
"mypkg/*.py" = [
  "D100",
  "D101",
  "D102",
  "D103",
]

are not considered. Therefore, a D103 warning (missing docstring in public function) is reported by flycheck/python-ruff for every public function in mymod.py without a docstring.

Expected behavior

I expect that ruff specific settings in my project ruff.toml/pyproject.toml are not ignored.

System configuration

Syntax checkers for buffer mymod.py in python-ts-mode:

First checker to run:

  python-ruff
    - may enable:         yes
    - executable:         Found at /home/thomashisch/miniconda3/bin/ruff
    - configuration file: Found at "/tmp/ruff-example/ruff.toml"
    - next checkers:      python-mypy

Checkers that may run as part of the first checker's chain:

  python-mypy
    - may enable:         yes
    - may run:            t
    - executable:         Found at /home/thomashisch/micromamba/envs/py_secs/bin/mypy
    - configuration file: Not found

Checkers that could run if selected:

  python-pylint  select
    - may enable:         yes
    - executable:         Found at /home/thomashisch/micromamba/envs/py_secs/bin/python
    - configuration file: Found at "/home/thomashisch/.pylintrc"
    - `pylint' module:    Found at "/home/thomashisch/micromamba/envs/py_secs/lib/python3.12/site-packages/pylint/__init__.py"
    - next checkers:      python-mypy

  python-pycompile  select
    - may enable:    yes
    - executable:    Found at /home/thomashisch/miniconda3/bin/python3
    - next checkers: python-mypy

Checkers that are compatible with this mode, but will not run until properly configured:

  python-flake8 (automatically disabled) reset
    - may enable:         no
    - executable:         Found at /home/thomashisch/miniconda3/bin/python3
    - configuration file: Not found
    - `flake8' module:    Missing; sys.path is ['/home/thomashisch/miniconda3/lib/python311.zip', '/home/thomashisch/miniconda3/lib/python3.11', '/home/thomashisch/miniconda3/lib/python3.11/lib-dynload', '/home/thomashisch/.local/lib/python3.11/site-packages', '/home/thomashisch/miniconda3/lib/python3.11/site-packages', '/home/thomashisch/main/site_python']
    - next checkers:      python-pylint, python-mypy

  python-pyright (automatically disabled) reset
    - may enable: no
    - executable: Not found

Flycheck Mode is enabled. Use C-u C-c ! x to enable disabled checkers.

--------------------

Flycheck version: 20240317.606
Emacs version:    30.0.50
System:           x86_64-pc-linux-gnu
Window system:    x

Emacs configuration:

• Plain Emacs / Custom configuration
• Spacemacs
• Doom Emacs
• Other shared configuration

Additional notes

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