getInTreeDir :: IO String
getInTreeDir = getExecDir >>= \case
  Nothing -> error "No GhcDir found"
  Just d -> return (d </> ".." </> "lib")
getInTreeDir :: IO String
getInTreeDir = getExecDir >>= \case
  Nothing -> error "No GhcDir found"
  Just d -> return (d </> ".." </> "lib")
getInTreeDir = getExecDir >>= \case
  Nothing -> error "No GhcDir found"
  Just d -> return (d </> ".." </> "lib")