top-level: Close over fewer arguments for stdenv stages

This makes the flow of data easier to understand. There's little downside
because the args in question are already inspected by the stdenvs.

cross-compiling in particular is simpler because we don't need to worry
about overriding the config closed over by `allPackages`.

pkgs/stdenv/cross/default.nix

@@ -1,14 +1,14 @@
-{ system, allPackages, platform, crossSystem, config, ... } @ args:
+{ lib, allPackages
+, system, platform, crossSystem, config
+}:
 
 rec {
-  argClobber = {
+  vanillaStdenv = (import ../. {
+    inherit lib allPackages system platform;
     crossSystem = null;
     # Ignore custom stdenvs when cross compiling for compatability
     config = builtins.removeAttrs config [ "replaceStdenv" ];
-  };
-  vanillaStdenv = (import ../. (args // argClobber // {
-    allPackages = args: allPackages (argClobber // args);
-  })) // {
+  }) // {
     # Needed elsewhere as a hacky way to pass the target
     cross = crossSystem;
   };

pkgs/stdenv/custom/default.nix

@@ -1,10 +1,13 @@
-{ system, allPackages, platform, crossSystem, config, ... } @ args:
+{ lib, allPackages
+, system, platform, crossSystem, config
+}:
 
 rec {
-  vanillaStdenv = import ../. (args // {
+  vanillaStdenv = import ../. {
+    inherit lib allPackages system platform crossSystem;
     # Remove config.replaceStdenv to ensure termination.
     config = builtins.removeAttrs config [ "replaceStdenv" ];
-  });
+  };
 
   buildPackages = allPackages {
     inherit system platform crossSystem config;

pkgs/stdenv/darwin/default.nix

@@ -100,7 +100,7 @@ in rec {
       };
 
       thisPkgs = allPackages {
-        inherit system platform;
+        inherit system platform config;
         allowCustomOverrides = false;
         stdenv = thisStdenv;
       };

pkgs/stdenv/default.nix

@@ -5,12 +5,13 @@
 # Posix utilities, the GNU C compiler, and so on.  On other systems,
 # we use the native C library.
 
-{ system, allPackages ? import ../top-level, platform, config, crossSystem, lib }:
-
+{ # Args just for stdenvs' usage
+  lib, allPackages
+  # Args to pass on to `allPacakges` too
+, system, platform, crossSystem, config
+}:
 
 let
-
-
   # The native (i.e., impure) build environment.  This one uses the
   # tools installed on the system outside of the Nix environment,
   # i.e., the stuff in /bin, /usr/bin, etc.  This environment should
@@ -19,6 +20,7 @@ let
   inherit (import ./native { inherit system allPackages config; }) stdenvNative;
 
   stdenvNativePkgs = allPackages {
+    inherit system platform crossSystem config;
     allowCustomOverrides = false;
     stdenv = stdenvNative;
     noSysDirs = false;

pkgs/stdenv/linux/default.nix

@@ -106,7 +106,7 @@ rec {
       };
 
       thisPkgs = allPackages {
-        inherit system platform;
+        inherit system platform config;
         allowCustomOverrides = false;
         stdenv = thisStdenv;
       };

pkgs/stdenv/native/default.nix

@@ -126,7 +126,7 @@ rec {
   } // {inherit fetchurl;};
 
   stdenvBoot1Pkgs = allPackages {
-    inherit system;
+    inherit system platform config;
     allowCustomOverrides = false;
     stdenv = stdenvBoot1;
   };

pkgs/top-level/default.nix

@@ -69,9 +69,10 @@ in let
   # deterministically inferred the same way.
   nixpkgsFun = newArgs: import ./. (args // newArgs);
 
-  # Partially apply some args for building bootstraping stage pkgs sets
+  # Partially apply some arguments for building bootstraping stage pkgs
+  # sets. Only apply arguments which no stdenv would want to override.
   allPackages = newArgs: import ./stage.nix ({
-    inherit lib nixpkgsFun config;
+    inherit lib nixpkgsFun;
   } // newArgs);
 
   stdenv = import ../stdenv {