Site-specific drush.yml file not loaded

[grasmash]

Drush does not appear to load docroot/sites/default/drush.yml, although the documentation indicates that this should work.

Adding the following to drush/drush.yml has no effect:

drush:
  paths:
    config:
      - ../docroot/sites/default/drush.yml

Executing drush status --config=docroot/sites/default/drush.yml also does not load it.

[grasmash]

This may be 2 issues.

1. Site-specific drush.yml file not loaded automatically.
2. Custom drush.yml file is not loaded even when explicitly defined in drush.paths.config.

[grasmash]

Opened #3279 to address the second issue. Changed scope of this issue to only "Site-specific drush.yml file not loaded".

[hansfn]

I can confirm that of Drush 9.1.0 this issue is still present. If I create sites/default/drush.yml containing

options:
  uri: 'http://nonexisting.domain'

it has no effect for example when running drush status. If I move the file to vendor/drush/drush/drush.yml or ~/.drush/drush.yml it has the expected effect.

[grasmash]

This PR would address the issue, but I have no plans to continue work on it:
#3278

[weitzman]

The way to set URI early enough for this to work is to set the DRUSH_OPTIONS_URI env variable. See #3278 (comment).