neovim: cleanup a bit libluv related hacks

Remove unneeded cmakeFlags and explain more what is the difference
between lua.pkgs.libluv and lua.pkgs.luv.

pkgs/applications/editors/neovim/default.nix

@@ -21,14 +21,6 @@ let
     ));
 
   pyEnv = python3.withPackages(ps: with ps; [ pynvim msgpack ]);
-
-  # FIXME: this is verry messy and strange.
-  # see https://github.com/NixOS/nixpkgs/pull/80528
-  luv = lua.pkgs.luv;
-  luvpath = with builtins ; if stdenv.isDarwin
-    then "${luv.libluv}/lib/lua/${lua.luaversion}/libluv.${head (match "([0-9.]+).*" luv.version)}.dylib"
-    else "${luv}/lib/lua/${lua.luaversion}/luv.so";
-
 in
   stdenv.mkDerivation rec {
     pname = "neovim-unwrapped";
@@ -57,7 +49,11 @@ in
       libtermkey
       libuv
       libvterm-neovim
-      luv.libluv
+      # This is actually a c library, hence it's not included in neovimLuaEnv,
+      # see:
+      # https://github.com/luarocks/luarocks/issues/1402#issuecomment-1080616570
+      # and it's definition at: pkgs/development/lua-modules/overrides.nix
+      lua.pkgs.libluv
       msgpack
       ncurses
       neovimLuaEnv
@@ -97,12 +93,12 @@ in
     disallowedReferences = [ stdenv.cc ];
 
     cmakeFlags = [
-      "-DGPERF_PRG=${gperf}/bin/gperf"
-      "-DLUA_PRG=${neovimLuaEnv.interpreter}"
-      "-DLIBLUV_LIBRARY=${luvpath}"
+      # Don't use downloaded dependencies. At the end of the configurePhase one
+      # can spot that cmake says this option was "not used by the project".
+      # That's because all dependencies were found and
+      # third-party/CMakeLists.txt is not read at all.
       "-DUSE_BUNDLED=OFF"
     ]
-    ++ optional doCheck "-DBUSTED_PRG=${neovimLuaEnv}/bin/busted"
     ++ optional (!lua.pkgs.isLuaJIT) "-DPREFER_LUA=ON"
     ;
 

pkgs/development/lua-modules/overrides.nix

@@ -281,7 +281,7 @@ with prev;
   });
 
 
-  # as advised in https://github.com/luarocks/luarocks/issues/1402
+  # as advised in https://github.com/luarocks/luarocks/issues/1402#issuecomment-1080616570
   # we shouldn't use luarocks machinery to build complex cmake components
   libluv = pkgs.stdenv.mkDerivation {