Packaging/32bit Applications

Building software with 32bit gcc

Question: I'm invoking gcc with -m32 and it fails to find `gnu/stubs-32.h`
Answer (clever): you want to use pkgsi686Linux instead of pkgs, so things like pkgsi686Linux.stdenv.mkDerivation or pkgsi686Linux.callPackage then nix will give you 32bit everything

Building software with both 32- and 64-bit executables

If a package wants to compile both 32/64-bit executables, you need a compiler with multilib support. Nixpkgs provides multiStdenv.mkDerivation that should be used instead stdenv.mkDerivation. This is equivalent to using gcc-multilib in debian derivatives.