$ git clone -n https://src.fedoraproject.org/rpms/perl-XML-Namespace.git /var/lib/mock/f45-build-27502-624/root/chroot_tmpdir/scmroot/perl-XML-Namespace
Cloning into '/var/lib/mock/f45-build-27502-624/root/chroot_tmpdir/scmroot/perl-XML-Namespace'...
$ git fetch origin 375b4e12cb80f3fe2ad6b7c7dc02618dc27399e6:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/perl-XML-Namespace
 * [new ref]         375b4e12cb80f3fe2ad6b7c7dc02618dc27399e6 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 375b4e1 Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild