runCommand: Use stdenvNoCC

This ensures that most "trivial" derivations used to build NixOS
configurations no longer depend on GCC. For commands that do invoke
gcc, there is runCommandCC.

nixos/modules/system/boot/stage-1.nix

@@ -34,7 +34,7 @@ let
   # copy what we need.  Instead of using statically linked binaries,
   # we just copy what we need from Glibc and use patchelf to make it
   # work.
-  extraUtils = pkgs.runCommand "extra-utils"
+  extraUtils = pkgs.runCommandCC "extra-utils"
     { buildInputs = [pkgs.nukeReferences];
       allowedReferences = [ "out" ]; # prevent accidents like glibc being included in the initrd
     }

nixos/tests/boot-stage1.nix

@@ -62,7 +62,7 @@ import ./make-test.nix ({ pkgs, ... }: {
     boot.initrd.kernelModules = [ "kcanary" ];
 
     boot.initrd.extraUtilsCommands = let
-      compile = name: source: pkgs.runCommand name { inherit source; } ''
+      compile = name: source: pkgs.runCommandCC name { inherit source; } ''
         mkdir -p "$out/bin"
         echo "$source" | gcc -Wall -o "$out/bin/$name" -xc -
       '';

pkgs/build-support/trivial-builders.nix

@@ -1,15 +1,23 @@
-{ lib, stdenv, lndir }:
+{ lib, stdenv, stdenvNoCC, lndir }:
+
+let
+
+  runCommand' = stdenv: name: env: buildCommand:
+    stdenv.mkDerivation ({
+      inherit name buildCommand;
+      passAsFile = [ "buildCommand" ];
+    } // env);
+
+in
 
 rec {
 
   # Run the shell command `buildCommand' to produce a store path named
   # `name'.  The attributes in `env' are added to the environment
   # prior to running the command.
-  runCommand = name: env: buildCommand:
-    stdenv.mkDerivation ({
-      inherit name buildCommand;
-      passAsFile = [ "buildCommand" ];
-    } // env);
+  runCommand = runCommandNoCC;
+  runCommandNoCC = runCommand' stdenvNoCC;
+  runCommandCC = runCommand' stdenv;
 
 
   # Create a single file.

pkgs/top-level/default.nix

@@ -82,7 +82,7 @@ let
 
       trivialBuilders = self: super:
         (import ../build-support/trivial-builders.nix {
-          inherit lib; inherit (self) stdenv; inherit (self.xorg) lndir;
+          inherit lib; inherit (self) stdenv stdenvNoCC; inherit (self.xorg) lndir;
         });
 
       stdenvDefault = self: super: (import ./stdenv.nix topLevelArguments) {} pkgs;