pylsp-mypy not recognizing correct Python version

[yanniskatsaros]

I have a Python 3.11.9 project (MacOS Sonoma 14.5 (23F79) - M1 Pro) configured using solely a pyproject.toml. I am using a venv with all project dependencies installed and LSP is working correctly in my editor (Helix) and pylsp-mypy is correctly showing typing errors/diagnostics in my editor. (Note: python-lsp-server and pylsp-mypy are both installed in this project's virtual environment.)

However, I am getting an LSP error in my editor when using structural pattern matching:

Pattern matching is only supported in Python 3.10 and greater (syntax)

When I manually run mypy in my terminal I do not get this error. I tried deleting the entire .mypy_cache directory as well and re-starting LSP etc. but this did not fix the issue.

The following is a snippet of relevant information found in my pyproject.toml:

# ... snip ...

[tool.mypy]
python_version = "3.11"
strict = true
plugins = [
  # https://docs.pydantic.dev/1.10/mypy_plugin/
  "pydantic.mypy",
]

# ... snip ...

[tool.pylsp-mypy]
enabled = true
live_mode = false
dmypy = false
strict = true
exclude = [
  "build",
  "**/.git",
  "**/.github",
  "**/.aws-sam",
  "**/.venv",
  "**/.vscode",
  "**/node_modules",
  "**/__pycache__",
  "**/.mypy_cache",
  "**/.ruff_cache",
]

I even tried the overrides attribute but without any success:

[tool.pylsp-mypy]
# ...
overrides = [
    "--python-version",
    "3.11",
]

I even checked the python-lsp-server configuration documentation did not find anything relevant to Python version configuration. Can anyone please help me out, is there something I have misconfigured or is this a bug?

[Richardk2n]

Are you sure, that this output is from mypy? There are likely other plugins running as well. The mypy section in your pyprojectl.toml looks fine to me.

[yanniskatsaros]

@Richardk2n you're right, I think this is actually an issue with python-lsp-ruff. I'll go ahead and close this and open an issue there. Sorry about that, thanks!