meson: host_machine.system() isn't our SYSTEM

[roberth]

Originally posted in #10908 (comment)

This is probably wrong. host_machine.system() is expected to have e.g. 'linux' in other places.

I don't know how to get the right value, reliably, and we've defined it to be based on autoconf, which I don't think we want to continue doing, or do we? Alternatively, we could leave it to the packager, and pass stdenv.hostPlatform.system in our own packaging?

[Ericson2314]

We now have

nix/src/libstore/meson.build

Line 25 in b89eca9

configdata.set_quoted('SYSTEM', host_machine.cpu_family() + '-' + host_machine.system())

which is correct / a lot closer to being correct.

See https://mesonbuild.com/Reference-tables.html