Is there a way to abort the "arc lint + arc unit" build step

On our installation I have managed to create buildables which never finish building.

I added a Herald rule kicking off a build of build plan 1 (arc lint + arc unit), whenever there is a commit. I use the history.immutable setting, so when I land a feature, all the intermediate commits are pushed. Each of these commits get a build, but the build plan is stuck in a “Waiting for messages” state.

As the build plan is not owned by anyone, nobody can abort the build.

Is there any way to abort the builds?

phabricator version: 6bfa990254a2, Tue, Feb 23
arcanist version: e95afd1d005c, Fri, Feb 19