$ git clone -n https://src.fedoraproject.org/rpms/rubygem-abrt.git /var/lib/mock/f45-build-34743-691/root/chroot_tmpdir/scmroot/rubygem-abrt
Cloning into '/var/lib/mock/f45-build-34743-691/root/chroot_tmpdir/scmroot/rubygem-abrt'...
$ git fetch origin 3251c1658399b1d8720fc92801bbc43b85bd8691:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rubygem-abrt
 * [new ref]         3251c1658399b1d8720fc92801bbc43b85bd8691 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 3251c16 Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild