Without the change eval fails as:

$ nix build --no-link -f. haskell.packages.ghc98.ghc-lib
error:
   … in the left operand of the update (//) operator
     at pkgs/development/haskell-modules/lib/compose.nix:40:7:
       39|     mkDerivation = drv: (args.mkDerivation drv).override f;
       40|   })) // {
         |       ^
       41|     overrideScope = scope: overrideCabal f (drv.overrideScope scope);

   error: attribute 'ghc-lib_9_8_1_20231121' missing
   at pkgs/development/haskell-modules/configuration-ghc-9.8.x.nix:58:26:
       57|   ghc-lib-parser-ex = doDistribute self.ghc-lib-parser-ex_9_8_0_2;
       58|   ghc-lib = doDistribute self.ghc-lib_9_8_1_20231121;
         |                          ^
       59|   megaparsec = doDistribute self.megaparsec_9_6_1;

Description of changes

Things done

• Built on platform(s)
  • x86_64-linux
  • aarch64-linux
  • x86_64-darwin
  • aarch64-darwin
• For non-Linux: Is sandboxing enabled in nix.conf? (See Nix manual)
  • sandbox = relaxed
  • sandbox = true
• Tested, as applicable:
  • NixOS test(s) (look inside nixos/tests)
  • and/or package tests
  • or, for functions and "core" functionality, tests in lib/tests or pkgs/test
  • made sure NixOS tests are linked to the relevant packages
• Tested compilation of all packages that depend on this change using nix-shell -p nixpkgs-review --run "nixpkgs-review rev HEAD". Note: all changes have to be committed, also see nixpkgs-review usage
• Tested basic functionality of all binary files (usually in ./result/bin/)
• 24.05 Release Notes (or backporting 23.05 and 23.11 Release notes)
  • (Package updates) Added a release notes entry if the change is major or breaking
  • (Module updates) Added a release notes entry if the change is significant
  • (Module addition) Added a release notes entry if adding a new NixOS module
• Fits CONTRIBUTING.md.

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