-cd doc; (pids=(); for f in `ls *rst`; do python3 /usr/bin/sphinx-build -b doctest . build $f & pids+=($!); done; for p in "${pids[@]}"; do wait $p; done)
-cd doc; (pids=(); for f in `ls *rst`; do python3 /usr/bin/sphinx-build -b doctest . build $f & pids+=($!); done; for p in "${pids[@]}"; do wait $p; done)