$ git clone -n https://src.fedoraproject.org/rpms/google-gson.git /var/lib/mock/f40-build-1236433-22898/root/chroot_tmpdir/scmroot/google-gson
Cloning into '/var/lib/mock/f40-build-1236433-22898/root/chroot_tmpdir/scmroot/google-gson'...
$ git fetch origin 41f08d6ed179f65db40fd5f02f0d6a0e7807d126:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/google-gson
 * [new ref]         41f08d6ed179f65db40fd5f02f0d6a0e7807d126 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 41f08d6 Merge branch 'f40' into rawhide