Build works using Git plugin 1.1.26. Upgrading to 1.2.0 causes build to fail. Downgrading plugin back to 1.1.26 restores the build.

Fetching changes from 1 remote Git repository
Fetching upstream changes from origin
No candidate revisions
ERROR: Couldn't find any revision to build. Verify the repository and branch configuration for this job.
Archiving artifacts
Recording test results
Finished: FAILURE

I'm using a parameterized build with environment variables for repository url and branch specifier. The build is triggered with leeroy which uses GIT_BASE_REPO, GIT_HEAD_REPO, GIT_SHA1, GITHUB_URL.

https://github.com/litl/leeroy

There's also another issue.
java.lang.UnsupportedOperationException: getCandidateRevisions method must be overridden

Uninstalling git, git-client, rebooting, then installing git, git-client and rebooting once more appears to have fixed getCandidateRevisions. No candidate revisions still occurs though.