cc-multilib-test> checking whether compiler builds valid 32bit C++ binaries... /nix/store/lm7bpsys535kxfljlkpw23l9k3rvbsgl-cxx-main.cc:1:10: fatal error: 'iostream' file not found
cc-multilib-test> #include <iostream>
cc-multilib-test> ^~~~~~~~~~
cc-multilib-test> 1 error generated.
tests.cc-multilib-clang
https://github.com/NixOS/nixpkgs/blob/master/pkgs/test/cc-wrapper/multilib.nix