Linux, why is HOMEBREW_ARCH deprecated? I need it to put HOMEBREW_PREFIX on NFS

[wscott]

Additional Info

• I am using Windows Subsystem for Linux

Output of brew config

na

Output of brew doctor

na

Description of issue

I see that in the 7.0 release the config HOMEBREW_ARCH is listed as deprecated and it will behave as if you used 'native' in the future. This means that any packages that are compiled will used the latest architecture features of the machine doing the building. I did search for a reason for this change, but I failed to find a place where it was discussed and the reason given.

I use homebrew in an environment with a large mixture of x86 machines with different processors and put the HOMEBREW_PREFIX on a shared NFS disk so multiple people can use it. Without HOMEBREW_ARCH, I would need to do all builds on the oldest machine to make sure these packages can be used by all clients.

Yes, I understand this isn't really a "supported" configuration, but it is useful when you have to deal with a work environment where the standard "stable" Linux configuration is very old and doesn't include the tools users want to use.

[SMillerDev]

The default configuration sets the arch to core2, unless the formula defines that the software has runtime detection of the CPU features. Did you run into issues without defining the arch? Or did you set it out of an abundance of caution?

[wscott]

If the default is core2 then that is fine. I am reacting to the 7.0 release notes that says that HOMEBREW_ARCH defaults to "Default native CPU optimisation". I read that as -march=native. And I know when I tried that in the past it didn't work in my setup.

[carlocab]

You can use brew install --build-bottle to use the same -march= flags we use for bottle builds, to make sure your builds are portable across CPUs. This skips postinstall, so you'll also need to call brew postinstall manually after.

Or, you can just install the bottles (i.e. don't build from source) which should just work on your various machines.