leanify: support darwin

pkgs/tools/misc/leanify/default.nix

@@ -1,6 +1,7 @@
 { lib
 , stdenv
 , fetchFromGitHub
+, libiconv
 }:
 
 stdenv.mkDerivation rec {
@@ -14,6 +15,14 @@ stdenv.mkDerivation rec {
     hash = "sha256-KxVV7AW9sEfH4YTPDfeJk7fMMGh0eSkECXM/Mv9XqBA=";
   };
 
+  postPatch = lib.optionalString stdenv.isDarwin ''
+    substituteInPlace Makefile \
+      --replace "-flto" "" \
+      --replace "lib/LZMA/Alloc.o" "lib/LZMA/CpuArch.o lib/LZMA/Alloc.o"
+  '';
+
+  buildInputs = lib.optionals stdenv.isDarwin [ libiconv ];
+
   installPhase = ''
     runHook preInstall
 
@@ -35,6 +44,5 @@ stdenv.mkDerivation rec {
     license = licenses.mit;
     maintainers = [ maintainers.mynacol ];
     platforms = platforms.all;
-    broken = stdenv.isDarwin;
   };
 }