Changes to default composition order

Default composition order is changing in Hydra 1.1.

For this example, let's assume the following two configs:

config.yaml

defaults:

- foo: bar

foo:

x: 10

foo/bar.yaml

# @package _group_

x: 20

In Hydra 1.0, configs from the Defaults List are overriding config.yaml, resulting in the following output:

foo:

x: 20

As of Hydra 1.1, config.yaml is overriding configs from the Defaults List, resulting in the following output:

foo:

x: 10

Migration

For the majority of applications, this will not cause issues. If your application requires the previous behavior, you can achieve it by adding _self_ as the first item in your Defaults List:

config.yaml

defaults:

- _self_

- foo: bar

foo:

x: 10

Output config

foo:

x: 20

The Defaults List is described here.