readIncludeDirs :: File -> EitherT MafiaError IO [Path]
readIncludeDirs package = do
  contents <- readUtf8 package
  return $
    case contents of
     Nothing -> []
     Just txt -> concatMap parseLine $ T.lines txt
readIncludeDirs :: File -> EitherT MafiaError IO [Path]
readIncludeDirs package = do
  contents <- readUtf8 package
  return $
    case contents of
     Nothing -> []
     Just txt -> concatMap parseLine $ T.lines txt
readIncludeDirs package = do
  contents <- readUtf8 package
  return $
    case contents of
     Nothing -> []
     Just txt -> concatMap parseLine $ T.lines txt