awesome, led me to use a dash script
#!/bin/sh
# https://discuss.ocaml.org/t/dune-how-to-link-statically-on-linux-not-on-others/8537/4?u=mro
case "$(uname -s)" in
Darwin)
# do not link statically on macos.
echo '()'
;;
*)
echo '(-ccopt "-static")'
;;
esac
had postponed that ever since and resolved now, thanks @lindig, @nojb