Use phases whitelist instead of dont*

flake.nix

@@ -21,9 +21,7 @@
 
         # The build is simply a call to makeWrapper, so we don't have to
         # do any of the typical build steps.
-        dontUnpack = true;
-        dontConfigure = true;
-        dontBuild = true;
+        phases = [ "installPhase" ];
 
         nativeBuildInputs = [ pkgs.makeWrapper ];
         # makeBinaryWrapper creates a stack executable for us that uses