$ git clone -n https://src.fedoraproject.org/rpms/bigloo.git /var/lib/mock/f40-build-2260858-54423/root/chroot_tmpdir/scmroot/bigloo
Cloning into '/var/lib/mock/f40-build-2260858-54423/root/chroot_tmpdir/scmroot/bigloo'...
$ git fetch origin 832029846425f037ec1bf0268d4a02f7ca5f51c8:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/bigloo
 * [new ref]         832029846425f037ec1bf0268d4a02f7ca5f51c8 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 8320298 Minor simplification of javac patch