anchor.diff:    skipOptionalDependencies ? [],
   
     # List or set of development dependencies (or null). These will only be
  -  # installed when `installDevDependencies` is true, which is provided by
  +  # installed when `includeDevDependencies` is true, which is provided by
     # the `.env` attribute.
     devDependencies ? null,
   
  
positive.code: 
  in
  
  if doCheck && (devDependencies == null)
  then throw ("${uniqueName}: Can't run tests because devDependencies have " +
              "not been defined.")
  else
  
  let
  
negative.code:         # that's not required). It will build the package with its dev
          # dependencies. This means that the package must have dev dependencies
          # defined, or it will error.
          env = buildNodePackage (args // {includeDevDependencies = true;});
  
          # An 'overrideNodePackage' attribute, which will call
          # `buildNodePackage` with the given arguments overridden.
  