composer job runs when OPT_IN_TEST_CURRENT=0 and SKIP_ESLINT=1

That's not the way the templates work. Evertyhing is documented in https://project.pages.drupalcode.org/gitlab_templates/jobs/, in the "When do the jobs run?" section.

What you need (as mentioned in the slack there https://drupal.slack.com/archives/C08CJ9K74MB/p1749769260020559) is the following:

composer:
  variables:
    DRUPAL_CORE: 10.2.0

Looking at the MR from the example pipeline, and the linked Slack thread, I can see what rosk0 was trying (to run all linting against D10 not D11) and it was not unreasonable to attempt it in that way. Maybe we can improve the documentation to help explain this, as rosk0 did take time to read the pages, he just made infererences that happend to be wrong.

I'd be happy to improve documentation.

Maybe we can add a section in here: https://project.pages.drupalcode.org/gitlab_templates/info/variants/

Yes the variants page would be a good place for something.

Also the validation jobs could have a paragraph, as that is where the problem started from. All linting jobs run with the 'current' variant, so if you want linting on a diferent one, you need to change what 'current' is percieved to be. The changes that rosk0 was trying to make was to alter the needs: for all the linting jobs, which was a perfectly reasonable thing to try.