use NixPkgs haskell-updates branch

Author: peterbecich

flake.lock

@@ -1,6 +1,6 @@
 {
   inputs = {
-    nixpkgs.url = "github:nixos/nixpkgs";
+    nixpkgs.url = "github:nixos/nixpkgs/haskell-updates";
     flake-parts.url = "github:hercules-ci/flake-parts";
     haskell-flake.url = "github:srid/haskell-flake";
     flake-root.url = "github:srid/flake-root";
@@ -79,8 +79,8 @@
               { custom = _: super.ghc-lib-parser-ex_9_12_0_0; };
             ghc-lib-parser = { super, ... }:
               {
-                # custom = _: super.ghc-lib-parser_9_12_2_20250421;
-                custom = _: super.ghc-lib-parser_9_12_2_20250320;
+                custom = _: super.ghc-lib-parser_9_12_2_20250421;
+                # custom = _: super.ghc-lib-parser_9_12_2_20250320;
               };
           };
           packages = {