$ git clone -n https://src.fedoraproject.org/rpms/gdb.git /var/lib/mock/f45-bootstrap-258-152/root/chroot_tmpdir/scmroot/gdb
Cloning into '/var/lib/mock/f45-bootstrap-258-152/root/chroot_tmpdir/scmroot/gdb'...
$ git fetch origin eb2fe315950b0ed53c9645515d31fab59b2f1373:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/gdb
 * [new ref]         eb2fe315950b0ed53c9645515d31fab59b2f1373 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at eb2fe31 Fix duplicate patch.