$ git clone -n https://src.fedoraproject.org/rpms/gperf.git /var/lib/mock/f45-build-12925-444/root/chroot_tmpdir/scmroot/gperf
Cloning into '/var/lib/mock/f45-build-12925-444/root/chroot_tmpdir/scmroot/gperf'...
$ git fetch origin 56b4be1b9c7b981ee76d593232508103d4a00a4d:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/gperf
 * [new ref]         56b4be1b9c7b981ee76d593232508103d4a00a4d -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 56b4be1 Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild