$ git clone -n https://src.fedoraproject.org/rpms/gap-pkg-polymaking.git /var/lib/mock/f45-build-52103-907/root/chroot_tmpdir/scmroot/gap-pkg-polymaking
Cloning into '/var/lib/mock/f45-build-52103-907/root/chroot_tmpdir/scmroot/gap-pkg-polymaking'...
$ git fetch origin 2788b07a5677e43b5190df525540287c5f37ae01:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/gap-pkg-polymaking
 * [new ref]         2788b07a5677e43b5190df525540287c5f37ae01 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 2788b07 Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild