$ git clone -n https://src.fedoraproject.org/rpms/mozc.git /var/lib/mock/f40-build-2097045-50426/root/chroot_tmpdir/scmroot/mozc
Cloning into '/var/lib/mock/f40-build-2097045-50426/root/chroot_tmpdir/scmroot/mozc'...
$ git fetch origin 2f3d6bf3b31dc4f42026ac3b9eb0067b7d3a771e:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/mozc
 * [new ref]         2f3d6bf3b31dc4f42026ac3b9eb0067b7d3a771e -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 2f3d6bf Add missing BuildRequires: desktop-file-utils