Unfortunately, since no one has answered yet, it indeed may be too complex for the forum, @dev! You can always connect with our support team (support@gitlab.com) ! and in the meantime, I will continue to try and find an expert here at GitLab who can help!
Yes there is. Under status click where it says cancelled/passed/failed, or whatever to open up the pipeline. Then in to right there is a retry and delete button. I’ve just deleted two of mine in exactly the same way. Either that or you don’t have the permissions for deleting it.
Click on the red box where it says Failed on the left hand side of your image under the status column. It will open, and then you will have like on my screenshot to be able to delete. This is why I cut the first screenshot to show just the status column.
Yep, just confirmed this on my test instance. Owner has the GUI option for deleting from the list of pipelines. The user I created as a maintainer in the GUI cannot. From one of the Gitlab 11.x versions functionality for a maintainer to delete pipelines via API was added, so this should be a way of deleting.
Although surprised that the GUI doesn’t allow both maintainers or owners to delete, but then I guess there must be a reason for it.
I created a “maintainer” Personal Access Token with all the permissions (api, read_api, read_repository, write_repository, read_registry, write_registry) but it doesn’t seem to be enough: