$ git clone -n https://src.fedoraproject.org/rpms/java-latest-openjdk.git /var/lib/mock/f42-build-side-1-3583956-46891/root/chroot_tmpdir/scmroot/java-latest-openjdk
Cloning into '/var/lib/mock/f42-build-side-1-3583956-46891/root/chroot_tmpdir/scmroot/java-latest-openjdk'...
$ git fetch origin b09c42fae72b65e9154b5d40a69b021a435b002d:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/java-latest-openjdk
 * [new ref]         b09c42fae72b65e9154b5d40a69b021a435b002d -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at b09c42f Bumped release