anchor.diff:  
     workOnMulti' = { env, packageNames, tools ? _: [], shellToolOverrides ? _: _: {} }:
       let inherit (builtins) listToAttrs filter attrValues all concatLists;
  -        combinableAttrs = [
  +        combinableAttrs = p: [
             "benchmarkDepends"
             "benchmarkFrameworkDepends"
             "benchmarkHaskellDepends"
  
positive.code:           "testSystemDepends"
            "testToolDepends"
          ];
          concatCombinableAttrs = haskellConfigs: lib.filterAttrs (n: v: v != []) (lib.listToAttrs (map (name: { inherit name; value = concatLists (map (haskellConfig: haskellConfig.${name} or []) haskellConfigs); }) combinableAttrs));
          getHaskellConfig = p: (overrideCabal p (args: {
            passthru = (args.passthru or {}) // {
              out = args;
  
negative.code:           "libraryToolDepends"
            "pkgconfigDepends"
            "setupHaskellDepends"
          ] ++ lib.optionals (p.doCheck or true) [
            "testDepends"
            "testFrameworkDepends"
            "testHaskellDepends"
  