1. Create a *new* job with two git repository URLs (note: two remotes, not MultiSCM). Ensure you name give the second one a different remote name. For example:

origin -> git://github.com/blt04/jenkins-test1.git
upstream -> git://github.com/blt04/jenkins-test2.git

2. Set the branch specifier to "remotes/origin/master"
3. Run the job.

Expected results:
Job runs with origin/master

Actual results:
Job does not run. Console log looks similar to:

Seen branch in repository origin/master
Seen branch in repository upstream/master
Seen branch in repository upstream/test2-only
Seen 3 remote branches
ERROR: Couldn't find any revision to build. Verify the repository and branch configuration for this job.

NOTE: This only occurs if you have never built the job before. If you've ever successfully built, this works fine.