[Bug] Recursive default list + Package overrides

[ppwwyyxx]

🐛 Bug

Description

Recursive default List + Package overrides not working. A continuation of #171 (comment)

To reproduce

Configs:

# model/maskrcnn.yaml:
# @package _group_
a: 1
b: 2

# model/maskrcnn2.yaml:
# @package _group_
b: 3
c: 4

defaults:
  - model/maskrcnn   # ??
  - _self_

# main.yaml:
defaults:
  - [email protected]: maskrcnn2

Code:

@hydra.main(config_name="main")
def my_app(cfg: DictConfig) -> None:
    print(cfg)

if __name__ == "__main__":
    my_app()

It gives me:

{'model': {'a': 1, 'b': 2, 'submodule': {'b': 3, 'c': 4}}}

Expected Behavior

I expect to get an equivalent of

model:
  submodule:
    a: 1
    b: 3
    c: 4

System information

• Hydra Version : master
• Python version : 3.8.6

[omry]

Thanks, something is off here, will take a look.

[omry]

This is a design issue with the current recursive defaults support.
I started to think about a design that switches addressing to be relative.
this is a very big change in how the recursive defaults will work.
Please check the design doc here and provide feedback.