$ git clone -n https://src.fedoraproject.org/rpms/xbar.git /var/lib/mock/f45-build-38607-725/root/chroot_tmpdir/scmroot/xbar
Cloning into '/var/lib/mock/f45-build-38607-725/root/chroot_tmpdir/scmroot/xbar'...
$ git fetch origin b2fb435789e7d1920c182db3a452fe58075ad107:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/xbar
 * [new ref]         b2fb435789e7d1920c182db3a452fe58075ad107 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at b2fb435 Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild