stdenv: throw from ghcjs.cc.outputs rather than ghcjs.cc

pkgs/stdenv/cross/default.nix

@@ -64,11 +64,17 @@ in lib.init bootStages ++ [
            else if crossSystem.useAndroidPrebuilt or false
              then buildPackages."androidndkPkgs_${crossSystem.ndkVer}".clang
            else if targetPlatform.isGhcjs
-             # Need to use `throw` so tryEval for splicing works, ugh.  Using
-             # `null` or skipping the attribute would cause an eval failure
-             # `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"
+             then {
+               # Need to use `throw` for the `outputs` attribute so tryEval for
+               # splicing works.  Using `null` or skipping the attribute would
+               # cause an eval failure that `tryEval` wouldn't catch, wrecking
+               # accessing previous stages when there is a C compiler and
+               # everything should be fine.
+               outputs = throw "no C compiler provided for this platform";
+               libc = "none";
+               isClang = false;
+               isGNU = false;
+             }
            else if crossSystem.isDarwin
              then buildPackages.llvmPackages.libcxxClang
            else if crossSystem.useLLVM or false

pkgs/top-level/splice.nix

@@ -64,9 +64,9 @@ let
             # on {}
             tryGetOutputs = value0:
               let
-                inherit (builtins.tryEval value0) success value;
+                inherit (builtins.tryEval (getOutputs value0)) success value;
               in
-              getOutputs (lib.optionalAttrs success value);
+                lib.optionalAttrs success value;
             getOutputs = value: lib.genAttrs
               (value.outputs or (lib.optional (value ? out) "out"))
               (output: value.${output});