Merge pull request #178408 from trofi/add-config.enableParallelBuildingByDefault

config.configurePlatformsByDefault: init option

pkgs/stdenv/generic/make-derivation.nix

@@ -111,9 +111,9 @@ let
 , # Target is not included by default because most programs don't care.
   # Including it then would cause needless mass rebuilds.
   #
-  # TODO(@Ericson2314): Make [ "build" "host" ] always the default.
+  # TODO(@Ericson2314): Make [ "build" "host" ] always the default / resolve #87909
   configurePlatforms ? lib.optionals
-    (stdenv.hostPlatform != stdenv.buildPlatform)
+    (stdenv.hostPlatform != stdenv.buildPlatform || config.configurePlatformsByDefault)
     [ "build" "host" ]
 
 # TODO(@Ericson2314): Make unconditional / resolve #33599

pkgs/top-level/config.nix

@@ -50,6 +50,10 @@ let
       feature = "set <literal>enableParallelBuilding</literal> to true by default";
     };
 
+    configurePlatformsByDefault = mkMassRebuild {
+      feature = "set <literal>configurePlatforms</literal> to <literal>[\"build\" \"host\"]</literal> by default";
+    };
+
     contentAddressedByDefault = mkMassRebuild {
       feature = "set <literal>__contentAddressed</literal> to true by default";
     };