$ git clone -n https://src.fedoraproject.org/rpms/guacamole-server.git /var/lib/mock/f45-build-13228-447/root/chroot_tmpdir/scmroot/guacamole-server
Cloning into '/var/lib/mock/f45-build-13228-447/root/chroot_tmpdir/scmroot/guacamole-server'...
$ git fetch origin 149afc1c3481dfaab83c8f554c3b099ee9fc4675:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/guacamole-server
 * [new ref]         149afc1c3481dfaab83c8f554c3b099ee9fc4675 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 149afc1 Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild