Version 2.1.8 breaks self-hosted macOS ARM Github Actions runner

[cknitt]

We have a self-hosted macOS ARM Github Actions runner for the ReScript CI.

Since setup-ocaml 2.1.8, we are getting the following error in CI on that runner (see e.g. https://github.com/rescript-lang/rescript-compiler/actions/runs/7117236442/job/19378552445):

Run ocaml/setup-ocaml@v2
Retrieve the opam cache
Install opam
Initialise the opam state
Error: Unable to locate executable file: brew. Please verify either the file path exists or the file can be found within a directory specified by the PATH environment variable. Also check the file mode to verify the file is executable.

This is probably due to this change? 2d84a0f

[smorimoto]

Yeah, that's definitely the cause.
Actually, this action doesn't officially support self-hosted runners yet.
I think the short term workaround is to expose the environment variable.

[cknitt]

I think the short term workaround is to expose the environment variable.

What exactly do you mean? Expose the environment variable where/how?

[smorimoto]

Just set GITHUB_ACTIONS to true on the runner.

[cknitt]

I tried:

1. Starting the self-hosted runner with GITHUB_ACTIONS=true ./run.sh. This did not have any effect.
2. Setting the variable in the Github actions admin UI. This is not allowed, see screenshot.

Am I missing something?

[smorimoto]

It's pretty weird that 1 doesn't work. How about explicitly exporting the environment variable globally?