brotli: fix darwin build

pkgs/tools/compression/brotli/default.nix

@@ -13,7 +13,7 @@ stdenv.mkDerivation rec {
     sha256 = "1rpg16zpr7h6vs7qr6npmqhyw4w5nkp24iq70s4dryn77m0r4mcv";
   };
 
-  buildInputs = [ cmake ];
+  nativeBuildInputs = [ cmake ];
 
   outputs = [ "out" "dev" "lib" ];
 
@@ -21,6 +21,10 @@ stdenv.mkDerivation rec {
   # and the wonderful bazel BUILD file is already there (yay case-insensitivity?)
   prePatch = "rm BUILD";
 
+  preConfigure = stdenv.lib.optionalString stdenv.isDarwin ''
+    cmakeFlagsArray+=("-DCMAKE_INSTALL_NAME_DIR=$lib/lib")
+  '';
+
   meta = with stdenv.lib; {
     inherit (src.meta) homepage;