Merge pull request #86223 from pikajude/darwin-static-eval

pkgsStatic: use clang for C compiler on Darwin

pkgs/stdenv/adapters.nix

@@ -15,7 +15,7 @@ rec {
   # Used to override packages in stdenv like Make.  Should not be used
   # for other dependencies.
   overrideInStdenv = stdenv: pkgs:
-    stdenv.override (prev: { allowedRequisites = null; extraBuildInputs = prev.extraBuildInputs or [] ++ pkgs; });
+    stdenv.override (prev: { allowedRequisites = null; extraBuildInputs = (prev.extraBuildInputs or []) ++ pkgs; });
 
 
   # Override the setup script of stdenv.  Useful for testing new
@@ -34,7 +34,7 @@ rec {
   makeStaticBinaries = stdenv:
     let stdenv' = if stdenv.hostPlatform.libc != "glibc" then stdenv else
       stdenv.override (prev: {
-          extraBuildInputs = prev.extraBuildInputs or [] ++ [
+          extraBuildInputs = (prev.extraBuildInputs or []) ++ [
               stdenv.glibc.static
             ];
         });

pkgs/stdenv/cross/default.nix

@@ -63,6 +63,8 @@ in lib.init bootStages ++ [
              # `tryEval` wouldn't catch, wrecking accessing previous stages
              # when there is a C compiler and everything should be fine.
              then throw "no C compiler provided for this platform"
+           else if crossSystem.isDarwin
+             then buildPackages.llvmPackages.clang
            else if crossSystem.useLLVM or false
              then buildPackages.llvmPackages_8.lldClang
            else buildPackages.gcc;