$ git clone -n https://src.fedoraproject.org/rpms/perl-CGI-Fast.git /var/lib/mock/f45-build-21967-589/root/chroot_tmpdir/scmroot/perl-CGI-Fast
Cloning into '/var/lib/mock/f45-build-21967-589/root/chroot_tmpdir/scmroot/perl-CGI-Fast'...
$ git fetch origin 826736b27b18f98217124bea1e8d97e2ac538cba:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/perl-CGI-Fast
 * [new ref]         826736b27b18f98217124bea1e8d97e2ac538cba -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 826736b Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild