$ git clone -n https://src.fedoraproject.org/rpms/rust-zopfli.git /var/lib/mock/f42-build-side-1-3523514-46210/root/chroot_tmpdir/scmroot/rust-zopfli
Cloning into '/var/lib/mock/f42-build-side-1-3523514-46210/root/chroot_tmpdir/scmroot/rust-zopfli'...
$ git fetch origin deeae2068b29f99fc0c5afb2df136ce54b6c0d6d:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-zopfli
 * [new ref]         deeae2068b29f99fc0c5afb2df136ce54b6c0d6d -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at deeae20 Update to 0.8.2 (close RHBZ#2360972)