$ git clone -n https://src.fedoraproject.org/rpms/libxml++.git /var/lib/mock/f45-build-17351-498/root/chroot_tmpdir/scmroot/libxml++
Cloning into '/var/lib/mock/f45-build-17351-498/root/chroot_tmpdir/scmroot/libxml++'...
$ git fetch origin 06b78a0e3dc401f9c02c66ff80d57fd554a1ec10:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/libxml++
 * [new ref]         06b78a0e3dc401f9c02c66ff80d57fd554a1ec10 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 06b78a0 Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild