$ git clone -n https://src.fedoraproject.org/rpms/check.git /var/lib/mock/f42-build-3275256-41320/root/chroot_tmpdir/scmroot/check
Cloning into '/var/lib/mock/f42-build-3275256-41320/root/chroot_tmpdir/scmroot/check'...
$ git fetch origin 3d070f6c9e9349bf172ea857c10e26194dbc3801:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/check
 * [new ref]         3d070f6c9e9349bf172ea857c10e26194dbc3801 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 3d070f6 Add patch to fix texinfo error