$ git clone -n https://src.fedoraproject.org/rpms/crontabs.git /var/lib/mock/f45-build-5700-341/root/chroot_tmpdir/scmroot/crontabs
Cloning into '/var/lib/mock/f45-build-5700-341/root/chroot_tmpdir/scmroot/crontabs'...
$ git fetch origin 1652cfdd2efd4b5d89102b88ca18802b83934c31:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/crontabs
 * [new ref]         1652cfdd2efd4b5d89102b88ca18802b83934c31 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 1652cfd Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild