$ git clone -n https://src.fedoraproject.org/rpms/lxappearance.git /var/lib/mock/f39-build-1465388-33579/root/chroot_tmpdir/scmroot/lxappearance
Cloning into '/var/lib/mock/f39-build-1465388-33579/root/chroot_tmpdir/scmroot/lxappearance'...
$ git fetch origin 21bddb43359df26beb1f4d3219be9e77e6681798:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/lxappearance
 * [new ref]         21bddb43359df26beb1f4d3219be9e77e6681798 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 21bddb4 Update to the latest git