YAML linter gives 500 when artifacts has wrong value

Summary

When .gitlab-ci.yml contains the following fragment, the yaml linter errors out.

deps:
  script: true
  artifacts:
    - anything

Steps to reproduce

Put the above fragment into the CI linter (e.g. https://gitlab.com/snowdrift/snowdrift/-/ci/lint ). Or, put it in your .gitlab-ci.yml and push your branch (repro: https://gitlab.com/snowdrift/snowdrift/pipelines/93325193)

Example Project

https://gitlab.com/snowdrift/snowdrift/pipelines/93325193

What is the current bug behavior?

"Undefined error" or an error code 500

What is the expected correct behavior?

Point out the semantic error in the yaml fragment. :)

Output of checks

This bug happens on GitLab.com.