Branches don't show up in the API Build Web UI unless a build has already been triggered on that branch


I would like to be able to trigger a custom build via the web UI on a feature branch using a subset of the jobs in my build matrix. I am currently able to do so via the API, so it seems that Travis knows my branch exists, but it doesn’t show up in the dropdown for the web UI for triggering custom builds because I’m skipping the builds per the rules in my .travis.yml:

I’m sure that some part of Travis’s API knows about my other branches besides master because they show up in the requests list.

Why isn’t the list of branches for my repo the same in Travis as in Github? Are there any plans to fix this?