Settings inheritance with ENV prefix does not work

[perminovs]

Bug

• OS: ubuntu 18.04
• Python version import sys; print(sys.version): 3.7.5 (default, Nov 7 2019, 10:50:52)
• Pydantic version import pydantic; print(pydantic.VERSION): 1.0b1 or 1.2, but works fine with 0.32

import os
from pydantic import BaseSettings


class MyBaseSettings(BaseSettings):
    var: int = 10


class MySubSettings(MyBaseSettings):
    class Config:
        env_prefix = 'PREFIX_'


os.environ['PREFIX_VAR'] = '2'
k = MySubSettings()
print(k.var)  # 10, but should be 2

We expect that k.var will be equal to 2, but it has default value 10.
It's reproduced since 1.0b1.

[samuelcolvin]

I'm looking into this, but I'm afraid the solution isn't trivial.

Weird that this got 11 👍 and 2 👀 in 2 hours. Any idea why this happened?

[kataev]

Yep, we are team.

[perminovs]

Thanks for quick support! Hope fix won't be difficult.

[livestreamx]

That's what exactly happens when you upgrade your project with Pydantic from 0.32 to 1.2 directly... Thank you for support, @samuelcolvin !

[samuelcolvin]

See #1093, should be fixed there.