$ git clone -n https://src.fedoraproject.org/rpms/gamescope.git /var/lib/mock/f41-build-854155-166804/root/chroot_tmpdir/scmroot/gamescope
Cloning into '/var/lib/mock/f41-build-854155-166804/root/chroot_tmpdir/scmroot/gamescope'...
$ git fetch origin d39de475b5503dadd73b68152a507aaaf554c84c:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/gamescope
 * [new ref]         d39de475b5503dadd73b68152a507aaaf554c84c -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at d39de47 Rebase to 3.15.11 (RHBZ#2313953)