Integration tests using the gcc compiler mostly fail on MacOS

[lukstafi]

Example of a failed run.
Example of a successful run.

According to "the internet", the problem on a particular MacOS system can be fixed by installing the XCode commandline tools: xcode-select --install. I have not verified this since I cannot reproduce the problem.

For me, currently almost all runs fail (I'd guess 99%); a few weeks ago, it felt like ~ 50% runs were failing.

Error message:

# /opt/homebrew/Cellar/gcc/13.2.0/lib/gcc/current/gcc/aarch64-apple-darwin23/13/include-fixed/stdio.h:78:10: fatal error: _stdio.h: No such file or directory
#    78 | #include <_stdio.h>
#       |          ^~~~~~~~~~

[lukstafi]

Ah! Could this be ocaml/opam#601 (comment) "On macOS having a gcc or binutils install that overrides xcode tools"?

( ocaml/opam#4837, ocaml/opam#4912, ocaml/opam#3650, ocaml/opam#5783 )