Use of stdlib dataclasses with BaseModel does not work as expected

[kschwab]

Initial Checks

• I confirm that I'm using Pydantic V2

Description

The following Pydantic example, Use of stdlib dataclasses with BaseModel, fails to work as expected.

Specifically, the ValidationError for file.filename input should be a valid string ... does not occur. Is this expected behavior?

Example Code

No response

Python, Pydantic & OS Version

$ python3 -c "import pydantic.version; print(pydantic.version.version_info())"
              pydantic version: 2.5.2
         pydantic-core version: 2.14.5
           pydantic-core build: profile=release pgo=true
                  install path: /usr/local/lib/python3.12/site-packages/pydantic
                python version: 3.12.0 (main, Oct  2 2023, 00:00:00) [GCC 13.2.1 20230918 (Red Hat 13.2.1-3)]
                      platform: Linux-6.2.9.valarch.master.1.1-x86_64-with-glibc2.38
              related packages: pydantic-settings-2.1.0 typing_extensions-4.9.0

[Kludex]

Yes. We need to add model_config = ConfigDict(revalidate_instances='always') to the Foo model to reproduce the expected behavior.

Also, we may want to improve the wording on this section.

[baohuamap]

Hi @Kludex , I can work on this issue.

[sydney-runkle]

@baohuamap,

Go for it! I can review a PR.

[patelnets]

Sorry for taking this, but I saw that baohuamap hadn't submitted a PR and it's been 5 days so I assumed it was fair game to create one.

Here is a PR for it #8491

[baohuamap]

Hi @patelnets, I've been waiting for any members to assign me this ticket to start working on it. But if you have done it, It's fine.

[patelnets]

Ahh sorry about that!