nixos/nix-ld: Support 32-bit portability

nixos/modules/programs/nix-ld.nix

@@ -1,61 +1,69 @@
 { pkgs, lib, config, ... }:
 let
-  cfg = config.programs.nix-ld;
+  suffixes = [ "nix-ld" "nix-ld-32" ];
+  variant = name: {
+    inherit name;
+    pkgs = { "nix-ld" = pkgs; "nix-ld-32" = pkgs.pkgsi686Linux; }.${name};
+    ldso = { "nix-ld" = "ldso"; "nix-ld-32" = "ldso32"; }.${name};
+    cfg = config.programs."${name}";
+  };
 
-  nix-ld-libraries = pkgs.buildEnv {
+  nix-ld-libraries = name: cfg: pkgs: pkgs.buildEnv {
     name = "ld-library-path";
     pathsToLink = [ "/lib" ];
     paths = map lib.getLib cfg.libraries;
     # TODO make glibc here configurable?
     postBuild = ''
-      ln -s ${pkgs.stdenv.cc.bintools.dynamicLinker} $out/share/nix-ld/lib/ld.so
+      ln -s ${pkgs.stdenv.cc.bintools.dynamicLinker} $out/share/${name}/lib/ld.so
     '';
-    extraPrefix = "/share/nix-ld";
+    extraPrefix = "/share/${name}";
     ignoreCollisions = true;
   };
 in
 {
   meta.maintainers = [ lib.maintainers.mic92 ];
-  options.programs.nix-ld = {
-    enable = lib.mkEnableOption ''nix-ld, Documentation: <https://github.com/Mic92/nix-ld>'';
-    package = lib.mkPackageOption pkgs "nix-ld" { };
-    libraries = lib.mkOption {
-      type = lib.types.listOf lib.types.package;
-      description = "Libraries that automatically become available to all programs. The default set includes common libraries.";
-      default = [ ];
-      defaultText = lib.literalExpression "baseLibraries derived from systemd and nix dependencies.";
-    };
-  };
+  options.programs = lib.genAttrs suffixes (suffix:
+    let inherit (variant suffix) name cfg pkgs; in {
+      enable = lib.mkEnableOption ''nix-ld, Documentation: <https://github.com/Mic92/nix-ld>'';
+      package = lib.mkPackageOption pkgs "nix-ld" { };
+      libraries = lib.mkOption {
+        type = lib.types.listOf lib.types.package;
+        description = "Libraries that automatically become available to all programs. The default set includes common libraries.";
+        default = [ ];
+        defaultText = lib.literalExpression "baseLibraries derived from systemd and nix dependencies.";
+      };
+    });
 
-  config = lib.mkIf config.programs.nix-ld.enable {
-    environment.ldso = "${cfg.package}/libexec/nix-ld";
+  config = lib.mkMerge (lib.forEach suffixes (suffix:
+    let inherit (variant suffix) name cfg pkgs ldso; in lib.mkIf config.programs.${name}.enable {
+      environment.${ldso} = "${cfg.package}/libexec/nix-ld";
 
-    environment.systemPackages = [ nix-ld-libraries ];
+      environment.systemPackages = [ (nix-ld-libraries name cfg pkgs) ];
 
-    environment.pathsToLink = [ "/share/nix-ld" ];
+      environment.pathsToLink = [ "/share/${name}" ];
 
-    environment.variables = {
-      NIX_LD = "/run/current-system/sw/share/nix-ld/lib/ld.so";
-      NIX_LD_LIBRARY_PATH = "/run/current-system/sw/share/nix-ld/lib";
-    };
+      environment.variables = {
+        "NIX_LD_${builtins.replaceStrings ["-"] ["_"] pkgs.system}" = "/run/current-system/sw/share/${name}/lib/ld.so";
+        "NIX_LD_LIBRARY_PATH_${builtins.replaceStrings ["-"] ["_"] pkgs.system}" = "/run/current-system/sw/share/${name}/lib";
+      };
 
-    # We currently take all libraries from systemd and nix as the default.
-    # Is there a better list?
-    programs.nix-ld.libraries = with pkgs; [
-      zlib
-      zstd
-      stdenv.cc.cc
-      curl
-      openssl
-      attr
-      libssh
-      bzip2
-      libxml2
-      acl
-      libsodium
-      util-linux
-      xz
-      systemd
-    ];
-  };
+      # We currently take all libraries from systemd and nix as the default.
+      # Is there a better list?
+      programs.nix-ld.libraries = with pkgs; [
+        zlib
+        zstd
+        stdenv.cc.cc
+        curl
+        openssl
+        attr
+        libssh
+        bzip2
+        libxml2
+        acl
+        libsodium
+        util-linux
+        xz
+        systemd
+      ];
+    }));
 }