🐛 Bug

Description

I want to instantiate recursively nested dataclass instances.

Because OmegaConf considers dataclasses instances to be configs, when calling _get_kwargs during the instantiate call, the dataclass instance is converted back to a config because parameters are added to a OmegaConf list / dict.

See https://github.com/facebookresearch/hydra/blob/c1eb2435b6314412d7029acbf87efd63d84d384c/hydra/_internal/utils.py#L685

Checklist

• I checked on the latest version of Hydra
• I created a minimal repro

To reproduce

In a script my_app.py

"""Test hydra dataclass instantiation."""

from dataclasses import dataclass
from omegaconf import OmegaConf
from hydra.utils import instantiate

@dataclass
class A:
    x: int

@dataclass
class B:
    a: A

conf = {
    "_target_": "__main__.B",
    "a": {
        "_target_": "__main__.A",
        "x": 1
    }
}
parsed = OmegaConf.create(conf)
instance = instantiate(parsed)
print(instance)

run python my_app.py.

You get

B(a={'x': 1})

Expected Behavior

I expect the result to be B(a=A(x=1)).

It seems strange to me that the config schema interferes with the instantiation.

I work with a codebase where a bunch of classes are dataclasses and using hydra for configuration would be a plus.

System information

• Hydra Version : master
• Python version : 3.6
• Virtual environment type and version : instantiated with python -m venv
• Operating system : macOS 11.0.1

Additional context

Add any other context about the problem here.