$ git clone -n https://src.fedoraproject.org/rpms/gtk+extra.git /var/lib/mock/f45-build-13174-447/root/chroot_tmpdir/scmroot/gtk+extra
Cloning into '/var/lib/mock/f45-build-13174-447/root/chroot_tmpdir/scmroot/gtk+extra'...
$ git fetch origin 86f7a9a2746d728817e72bc9f07bd37b1859b303:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/gtk+extra
 * [new ref]         86f7a9a2746d728817e72bc9f07bd37b1859b303 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 86f7a9a Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild