Currently, when a user hits their concurrency limits there is no error message. They will see their builds queueing.

The user can use the CircleCI v3 API to get unclaimed tasks for a given resource class(https://circleci.com/docs/runner-api/#get-api-v3-tasks) to confirm that they have unclaimed tasks.

At this time, user rely on CircleCI Support team to share a list of jobs that need to be cancelled.

This feature request is for better error messaging when concurrency limits are hit and for exposure to which jobs need to be cancelled in order to move forward.