Add initial support for opam 2.2 on Windows

[kit-ty-kate]

Closes #733
Closes #793

Joint work with @hhugo @smorimoto @dra27.

[smorimoto]

You can compile by running yarn build.

[smorimoto]

Could you rebase to the latest master?

[kit-ty-kate]

Could you rebase to the latest master?

done

You can compile by running yarn build.

that does not work. Do you have a list of command to run for javascript beginners? I have yarn installed but (after having to modify package.json to get the right yarn version or something), it's complaining about ncc.

[kit-ty-kate]

Note from @dra27: this should be part of ocaml/setup-ocaml@v3

[hhugo]

@kit-ty-kate, do you have some CI testing this GH action ?

[kit-ty-kate]

@hhugo I do in kit-ty-kate/mirage-torrent#2 but while the setup-ocaml succeeds, the builds fails while building dune:

#=== ERROR while compiling dune.3.15.2 ========================================#
# context     2.2.0~beta2 | win32/x86_64 | ocaml-base-compiler.4.14.2 | git+https://github.com/dra27/opam-repository.git#windows-initial
# path        D:\a\mirage-torrent\mirage-torrent\_opam\.opam-switch\build\dune.3.15.2
# command     D:\a\mirage-torrent\mirage-torrent\_opam\bin\ocaml.exe boot/bootstrap.ml -j 4
# exit-code   2
# env-file    D:\.opam\log\dune-8180-dff03d.env
# output-file D:\.opam\log\dune-8180-dff03d.out
### output ###
# ocamlc -output-complete-exe -w -24 -g -o .duneboot.exe -I boot unix.cma boot/libs.ml boot/duneboot.ml
# ** Cannot resolve symbols for D:/a/mirage-torrent/mirage-torrent/_opam/lib/ocaml\libcamlrun.a(startup_aux.b.o):
#  swscanf
# ** Cannot resolve symbols for descriptor object:
#  _vscwprintf
# File "boot/duneboot.ml", line 1:
# Error: Error while building custom runtime system

[hhugo]

I'm also testing this PR in https://github.com/hhugo/ocamlbuild/pull/7 and see the same error.

[hhugo]

The following can probably be removed as well

    // Works around the lack of https://github.com/ocaml/opam/pull/3882 when
    // adding ocaml/opam-repository on Windows. Can be removed when the action
    // switches to opam 2.2
    if (PLATFORM === "win32") {
      const autocrlf = await getExecOutput(
        "git",
        ["config", "--global", "core.autocrlf"],
        { ignoreReturnCode: true },
      );
      if (autocrlf.stdout.trim() !== "input") {
        if (autocrlf.exitCode === 0) {
          restore_autocrlf = autocrlf.stdout.trim();
        } else {
          restore_autocrlf = null; // Unset the value at the end
        }
      }
      await exec("git", ["config", "--global", "core.autocrlf", "input"]);
    }

[dra27]

No need to special case WIndows in the test matrix any more 😎

[hhugo]

When can we expect a release with this PR ?

[smorimoto]

I'm planning to release as follows, but do you all have any objections? @dra27 @hhugo @kit-ty-kate

1. Merge this PR to master
2. Release as v3.0.0-alpha (maybe we shouldn't create the v3 tag at this point)
3. Once we have tested widely and verified that there is no major problem, then release v3.0.0

[hhugo]

Sounds reasonable to me

[kit-ty-kate]

lgtm

[smorimoto]

https://github.com/ocaml/setup-ocaml/releases/tag/v3.0.0-alpha