Mypy Syntax Error Python 3.8

[pythonweb2]

Initial Checks

• I confirm that I'm using Pydantic V2

Description

The issue is explained in python/mypy#17768, but the author closed the issue with no indication it had been resolved or even reported.

Error Message: error: X | Y syntax for unions requires Python 3.10

Example Code

See related issue

Python, Pydantic & OS Version

OS: Ubuntu 20.04
Python: 3.8.10 (Version that ships with Ubuntu 20.04)
Pydantic: 2.9.2

[Viicos]

Well the error message is pretty clear? You are on Python 3.8, and this syntax was introduced in 3.10.

Pydantic will still be able to evaluate such expressions thanks to the eval_type_backport package, which needs to be manually installed.