$ git clone -n https://src.fedoraproject.org/rpms/libxdiff.git /var/lib/mock/f45-build-17341-498/root/chroot_tmpdir/scmroot/libxdiff
Cloning into '/var/lib/mock/f45-build-17341-498/root/chroot_tmpdir/scmroot/libxdiff'...
$ git fetch origin a58beeefaf794ac217a4f9859b7cf8751713e873:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/libxdiff
 * [new ref]         a58beeefaf794ac217a4f9859b7cf8751713e873 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at a58beee Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild