anchor.diff:      packageJSON,
       yarnLock,
       yarnNix ? mkYarnNix { inherit yarnLock; },
  +    offlineCache ? importOfflineCache yarnNix,
       yarnFlags ? defaultYarnFlags,
       pkgConfig ? {},
       preBuild ? "",
  
positive.code:     packageJSON ? src + "/package.json",
      yarnLock ? src + "/yarn.lock",
      yarnNix ? mkYarnNix { inherit yarnLock; },
      yarnFlags ? defaultYarnFlags,
      yarnPreBuild ? "",
      yarnPostBuild ? "",
  
negative.code:     workspaceDependencies ? [], # List of yarn packages
    }:
      let
        extraBuildInputs = (lib.flatten (builtins.map (key:
          pkgConfig.${key}.buildInputs or []
        ) (builtins.attrNames pkgConfig)));
  