$ git clone -n https://src.fedoraproject.org/rpms/gsm.git /var/lib/mock/f45-build-13073-446/root/chroot_tmpdir/scmroot/gsm
Cloning into '/var/lib/mock/f45-build-13073-446/root/chroot_tmpdir/scmroot/gsm'...
$ git fetch origin 618ebc6a03ca7393ba7b989e3db8928930cca23c:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/gsm
 * [new ref]         618ebc6a03ca7393ba7b989e3db8928930cca23c -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 618ebc6 Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild