anchor.diff:  , iosSdkVersion ? "10.2"
   , iosSdkLocation ? "/Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS${iosSdkVersion}.sdk"
   , iosSupportForce ? false
  +, nixpkgsOverlays ? []
   }:
   let iosSupport =
         if system != "x86_64-darwin" then false
         else if iosSupportForce || builtins.pathExists iosSdkLocation then true
         else builtins.trace "Warning: No iOS sdk found at ${iosSdkLocation}; iOS support disabled.  To enable, either install a version of Xcode that provides that SDK or override the value of iosSdkVersion to match your installed version." false;
  -    globalOverlay = self: super: {
  -      all-cabal-hashes = super.all-cabal-hashes.override {
  -        src-spec = {
  -          owner = "commercialhaskell";
  -          repo = "all-cabal-hashes";
  -          rev = "82a8a1a49240a1b465c95de6fa6bf56323ee858f";
  -          sha256 = "1jdzl5fyp1qcsi1anjig6kglq4jjsdll53nissjcnxpy3jscmarm";
  -        };
  -      };
  -    };
  +    globalOverlays = [
  +      (self: super: {
  +        all-cabal-hashes = super.all-cabal-hashes.override {
  +          src-spec = {
  +            owner = "commercialhaskell";
  +            repo = "all-cabal-hashes";
  +            rev = "82a8a1a49240a1b465c95de6fa6bf56323ee858f";
  +            sha256 = "1jdzl5fyp1qcsi1anjig6kglq4jjsdll53nissjcnxpy3jscmarm";
  +          };
  +        };
  +      })
  +    ] ++ nixpkgsOverlays;
       appleLibiconvHack = self: super: {
         darwin = super.darwin // {
           libiconv =
  
positive.code:       android = nixpkgs.lib.mapAttrs (_: args: if args == null then null else nixpkgsFunc args) rec {
          arm64 = {
            system = "x86_64-linux";
            overlays = [globalOverlay];
            crossSystem = {
              config = "aarch64-unknown-linux-android";
              arch = "arm64";
  
negative.code:     };
      nixpkgs = nixpkgsFunc ({
        inherit system;
        overlays = globalOverlays;
        config = {
          allowUnfree = true;
          allowBroken = true; # GHCJS is marked broken in 011c149ed5e5a336c3039f0b9d4303020cff1d86
  