David Allsopp

Quoting [the README](https://github.com/avsm/setup-ocaml#action): “**Windows**: Installs Cygwin”! It would be worth adding a sentence noting that `%CYGWIN_ROOT%` contains the location of the Cygwin installation and `setup-x86_64.exe` is dropped inside it. The...

I'm not yet clear what you're trying to achieve - why are you wanting to set-up Cygwin separately?

You _could_ still install the CI dependencies using an opam file - you simply need an opam file in your repo containing the required depext statements and then pin it...

I don't expect that the `shell` command takes cmd's environment variable syntax - perhaps `"${env:CYGWIN_ROOT}\bin\bash.exe"` works?

Looking at the workflow, I don't know whether you can do that in `defaults` - it depends on whether it evaluates the environment lazily or not.

(closed/re-opened to force GitHub to redo the merge commit and pull in the fix for AppVeyor)

Either is fine, although personally I prefer rebasing, please.

This PR would have allowed us to avoid the slip in #11002 fixed in #11066. https://github.com/dra27/ocaml/commit/4882f3e09b506ddea41b3b2e482731faeae357ab adds the necessary support to `configure` to add `-Wimplicit-fallthrough` to the C warnings enabled...

> To echo @xavierleroy from an opam perspective, this proposal would make the installation of trunk switches for users slightly more complicated, as they would also need to have the...

We only cared about the reproducibility of `configure` _because_ we commit it, because we need it be certain that a committed version was actually generated by autoconf and doesn’t contain...