$ git clone -n https://src.fedoraproject.org/rpms/plexus-compiler.git /var/lib/mock/f40-build-2078183-49592/root/chroot_tmpdir/scmroot/plexus-compiler
Cloning into '/var/lib/mock/f40-build-2078183-49592/root/chroot_tmpdir/scmroot/plexus-compiler'...
$ git fetch origin ad5739bfff9deac8dcf4651c77b04bb6bb5b9cdd:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/plexus-compiler
 * [new ref]         ad5739bfff9deac8dcf4651c77b04bb6bb5b9cdd -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at ad5739b Update javapackages test plan to f40