diff --git a/pkgs/os-specific/darwin/apple-sdk-11.0/default.nix b/pkgs/os-specific/darwin/apple-sdk-11.0/default.nix
index 8c9e16a6ca9a9..1133cca002a8b 100644
--- a/pkgs/os-specific/darwin/apple-sdk-11.0/default.nix
+++ b/pkgs/os-specific/darwin/apple-sdk-11.0/default.nix
@@ -31,10 +31,7 @@ let
     };
 
     installPhase = ''
-      cd Library/Developer/CommandLineTools/SDKs/MacOSX11.1.sdk
-
-      mkdir $out
-      cp -r System usr $out/
+      mv Library/Developer/CommandLineTools/SDKs/MacOSX11.1.sdk $out
     '';
   };
 
@@ -49,10 +46,7 @@ let
     };
 
     installPhase = ''
-      cd Library/Developer/CommandLineTools
-
-      mkdir $out
-      cp -r Library usr $out/
+      mv Library/Developer/CommandLineTools $out
     '';
   };
 
diff --git a/pkgs/os-specific/darwin/gen-frameworks.py b/pkgs/os-specific/darwin/gen-frameworks.py
index f6e981952f422..ec2a6c7c16ecd 100755
--- a/pkgs/os-specific/darwin/gen-frameworks.py
+++ b/pkgs/os-specific/darwin/gen-frameworks.py
@@ -3,6 +3,12 @@
 
 """
 Generate a frameworks.nix for a macOS SDK.
+
+You may point this tool at an Xcode bundled SDK, but more ideal is using the
+SDK from Nixpkgs. For example:
+
+SDK_PATH="$(nix-build --no-link -A darwin.apple_sdk_11_0.MacOSX-SDK)"
+./gen-frameworks.py "$SDK_PATH" > ./new-frameworks.nix
 """
 
 import json