Multiproject pipeline definition results in HTTP 500 status (internal error)

This definition in .gitlab-ci.yml causes CI API to fail with HTTP status 500:

sanity:test:
  stage: sanity
  only:
    - master
    - develop
    - wvxvw/sanity-integration
  variables:
    IMAGE: $CI_REGISTRY_IMAGE/$CI_COMMIT_REF_SLUG/release
    VERSION: None
  trigger:
    project: automation/sanity-test

If this feature doesn't work, I'd expect a more intelligent error, explaining that this is not possible / not supposed to work.

If the feature is supposed to work, then I'd expect it... to, well... work.

I also saw that this is an "old" way to do thing. The new way doesn't work entirely because CI_JOB_TOKEN does not allow you to perform API calls, and in particular not trigger other jobs on other projects. I don't know if you wanted or expected it not to work, but, as of right now there is no way to execute multiproject pipelines, unless one uses a personal token which allows use of API, but then the information about the original user starting the job is lost.