As the title, can I delete it? I didn’t see any button can do this.
Yes. It is possible to delete it.
The Delete from UI functionality was introduced in Gitlab v12.7, so it does not have all of the functionality that it could have (I don’t see why this functionality you’re requesting isn’t currently implemented though)
However, the Gitlab API has a Delete Pipeline endpoint that will successfully delete a pipeline that has invalid yaml.
Ohhh, I think I’m going to use the API to get the job done. I didn’t see an option to delete my pipeline in the status of yml invalid.
Turns out in newest release (12.10.6 now) has this option in GUI