opam 2.2's release cycle has fallen a bit behind the compiler's (actually because of the Windows support). It's an experimental branch, but this works with opam

opam 2.2's release cycle has fallen a bit behind the compiler's (actually because of the Windows support). It's an experimental branch, but this works with opam-repository-mingw to get a vanilla mingw-w64 build of OCaml 5.0.0: opam switch create 5.0 --repos=dra27=git+https://github.com/dra27/opam-repository#windows-compilers https://github.com/dra27/opam-repository#windows-compilers --packages=ocaml.5.0.0,ocaml-option-mingw