$ git clone -n https://src.fedoraproject.org/rpms/xml2.git /var/lib/mock/f45-build-38947-730/root/chroot_tmpdir/scmroot/xml2
Cloning into '/var/lib/mock/f45-build-38947-730/root/chroot_tmpdir/scmroot/xml2'...
$ git fetch origin 94140ec4d1c842c4d6dc27f5a342371f559f510a:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/xml2
 * [new ref]         94140ec4d1c842c4d6dc27f5a342371f559f510a -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 94140ec Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild