$ git clone -n https://src.fedoraproject.org/rpms/apache-commons-lang3.git /var/lib/mock/f40-build-2151750-50906/root/chroot_tmpdir/scmroot/apache-commons-lang3
Cloning into '/var/lib/mock/f40-build-2151750-50906/root/chroot_tmpdir/scmroot/apache-commons-lang3'...
$ git fetch origin fbe25155767535d8f012b5844504c9baa67eadca:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/apache-commons-lang3
 * [new ref]         fbe25155767535d8f012b5844504c9baa67eadca -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at fbe2515 Update to upstream version 3.14.0