OPAM repo for OCaml multicore development
opam update
opam switch create 4.10.0+multicore --packages=ocaml-variants.4.10.0+multicore,ocaml-secondary-compiler --repositories=multicore=git+https://github.com/ocamllabs/multicore-opam.git,default
opam install dune.2.6.2 domainslib