$ git clone -n https://src.fedoraproject.org/rpms/rng-tools.git /var/lib/mock/f41-build-775114-13519/root/chroot_tmpdir/scmroot/rng-tools
Cloning into '/var/lib/mock/f41-build-775114-13519/root/chroot_tmpdir/scmroot/rng-tools'...
$ git fetch origin c3b1113e27681f933b198549f4b4048ee9dc9057:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rng-tools
 * [new ref]         c3b1113e27681f933b198549f4b4048ee9dc9057 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at c3b1113 Update to the upstream v6.17 @ 2160b9c3