building on macOS with ARM

[qacwnfq]

Hey,

FluxML relies on sys/prctl.h and other sys files. These files are not available on linux.
Perhaps we can find a way to replace/remove them for macOS builds.

[mbeyss]

prctl is just used to attach a debugger. I never found that to be particularly useful anyhow.

The other includes from sys are all POSIX. could you confirm those are present?

• sys/types.h
• sys/stat.h
• sys/socket.h
• sys/un.h
• sys/utsname.h
• sys/wait.h