$ git clone -n https://src.fedoraproject.org/rpms/perl-CGI-Untaint.git /var/lib/mock/f45-build-21990-589/root/chroot_tmpdir/scmroot/perl-CGI-Untaint
Cloning into '/var/lib/mock/f45-build-21990-589/root/chroot_tmpdir/scmroot/perl-CGI-Untaint'...
$ git fetch origin e453c837af0584d706825c9d37401cd94a4df91c:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/perl-CGI-Untaint
 * [new ref]         e453c837af0584d706825c9d37401cd94a4df91c -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at e453c83 Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild