$ git clone -n https://src.fedoraproject.org/rpms/goocanvas.git /var/lib/mock/f45-build-12873-444/root/chroot_tmpdir/scmroot/goocanvas
Cloning into '/var/lib/mock/f45-build-12873-444/root/chroot_tmpdir/scmroot/goocanvas'...
$ git fetch origin 5d5407b43e8e057ebd0d8172586ce5d8ad4ed4e6:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/goocanvas
 * [new ref]         5d5407b43e8e057ebd0d8172586ce5d8ad4ed4e6 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 5d5407b Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild