$ git clone -n https://src.fedoraproject.org/rpms/rocjpeg.git /var/lib/mock/f43-build-side-110214-58990851-6569996/root/chroot_tmpdir/scmroot/rocjpeg
Cloning into '/var/lib/mock/f43-build-side-110214-58990851-6569996/root/chroot_tmpdir/scmroot/rocjpeg'...
$ git fetch origin 70ca33360f12c09182bb2116361c651c5b5f0292:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rocjpeg
 * [new ref]         70ca33360f12c09182bb2116361c651c5b5f0292 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 70ca333 Update to 6.4.0