$ git clone -n https://src.fedoraproject.org/rpms/fvwm3.git /var/lib/mock/f45-build-9359-403/root/chroot_tmpdir/scmroot/fvwm3
Cloning into '/var/lib/mock/f45-build-9359-403/root/chroot_tmpdir/scmroot/fvwm3'...
$ git fetch origin 4a5f3a121973a94152fa334b2b55d6a2ece17a20:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/fvwm3
 * [new ref]         4a5f3a121973a94152fa334b2b55d6a2ece17a20 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 4a5f3a1 Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild