pydantic: `pydantic-mypy` plugin is incompatible with `pyproject.toml` config in `mypy>0.900`

Bug

Output of python -c "import pydantic.utils; print(pydantic.utils.version_info())":

pydantic version: 1.8.2
pydantic compiled: True
   install path: /opt/venv/lib/python3.8/site-packages/pydantic
   python version: 3.8.5 (default, Sep 10 2020, 16:58:22)  [GCC 8.3.0]
       platform: Linux-5.10.25-linuxkit-x86_64-with-glibc2.2.5
optional deps. installed: ['typing-extensions']

The newest release of mypy (0.900-0.901) has introduced pyproject.toml configuration in addition to the older mypy.ini in accordance with PEP-518. However, the pydantic-mypy plugin still expects an INI-formatted config file, such that TOML-configured mypy with the plugin enabled results in a parse error:

Error constructing plugin instance of PydanticPlugin

Traceback (most recent call last):
  File "/opt/venv/bin/mypy", line 8, in <module>
    sys.exit(console_entry())
  File "/opt/venv/lib/python3.8/site-packages/mypy/__main__.py", line 11, in console_entry
    main(None, sys.stdout, sys.stderr)
  File "mypy/main.py", line 98, in main
  File "mypy/build.py", line 179, in build
  File "mypy/build.py", line 229, in _build
  File "mypy/build.py", line 475, in load_plugins
  File "mypy/build.py", line 453, in load_plugins_from_config
  File "pydantic/mypy.py", line 77, in pydantic.mypy.PydanticPlugin.__init__
  File "pydantic/mypy.py", line 114, in pydantic.mypy.PydanticPluginConfig.__init__
  File "/usr/local/lib/python3.8/configparser.py", line 697, in read
    self._read(fp, filename)
  File "/usr/local/lib/python3.8/configparser.py", line 1113, in _read
    raise e
configparser.ParsingError: Source contains parsing errors: 'pyproject.toml'
        [line 12]: ']\n'
        [line 17]: ']\n'
        [line 65]: ']\n'
...

Note that the plugin still works in mypy>0.900 provided an INI configuration file is still provided. To bring the plugin up to speed for the newest mypy releases I believe we’ll need a TOML parser option in addition to the default ConfigParser in the plugin constructor.

About this issue

Original URL
State: closed
Created 3 years ago
Reactions: 36
Comments: 21 (9 by maintainers)

Commits related to this issue

Update dependencies mypy 0.9xx updates will be postponed until the pydantic plugin achieves compatibility (samuelcolvin/pydantic#2895). ```text .venv ❯ poetry update Updating dependencies Resolving ... — committed to br3ndonland/inboard by br3ndonland 3 years ago
Move mypy configuration to .mypy.ini pydantic's mypy plugin doesn't yet work properly with pyproject.toml (https://github.com/samuelcolvin/pydantic/issues/2895, fixed but not yet released). — committed to jugmac00/lpcraft by cjwatson 3 years ago
fix(api): mypy cfg missing pydantic plugin (#859) Realized we weren't setting up the pydantic mypy plugin. Oops. https://pydantic-docs.helpmanual.io/mypy_plugin/#configuring-the-plugin rel: https:/... — committed to recipeyak/recipeyak by sbdchd 2 years ago

Most upvoted comments

Not making any promises, but I’ll try to get a new release out next week.

+17

samuelcolvin on Sep 5, 2021

1.9.0 release has been published with pyproject.toml support 🎉

https://pypi.org/project/pydantic/1.9.0/

johnthagen on Jan 3, 2022

Thanks, really excited to see this released.

christianbundy on Sep 13, 2021

@samuelcolvin Is there anything we can do to help you get a new release out? Would it be helpful if I made prep branch like this?

christianbundy on Nov 16, 2021

@Ierezell See #2908, which references this branch: https://github.com/jrwalk/pydantic/tree/toml-support

It also helps to thumb up the original comment in this issue so maintainers have a sense of the number of users this affects.

johnthagen on Jun 16, 2021

Reading the config will fail as soon as TOML-specific stuff is present in pyproject.toml. E.g. adding

[[tool.mypy.overrides]]
module = "main"
no_implicit_reexport = true

or similar should already be enough to break the ConfigParser.

hoefling on Jun 15, 2021

Should also update the user guide to show how to enable and configure the plugin for pyproject.toml. This will likely be what a vast majority of users will migrate to given how popular using pyproject.toml is becoming:

https://pydantic-docs.helpmanual.io/mypy_plugin/#enabling-the-plugin https://pydantic-docs.helpmanual.io/mypy_plugin/#configuring-the-plugin

johnthagen on Jun 14, 2021

Hi, I stumbled across this issue as I was trying to use the new norms (pyproject.toml) and I’m building an API with FastApi.

Is there a branch or something I can help you testing with ?

Have a great day.

ierezell on Jun 16, 2021

@johnthagen yep, I’ve got that in a PR I’m working on!

jrwalk on Jun 14, 2021

@Ierezell feel free to use the branch @johnthagen linked, that should resolve it. And ++ to the thumbs-up as well - that mypy release is super fresh as well, so it just wouldn’t have surfaced until very recently.

In the meantime, everything should work perfectly happily with mypy>0.900, just with the config in mypy.ini rather than pyproject.toml - and converting the config options back and forth is straightforward (the PR has an example to be added to the pydantic docs).

jrwalk on Jun 16, 2021