How can I use annotations to customize HLint and mark my Haskell package as Safe?

Question

In my package I have several annotations to help customize my use of hlint :

{-# ANN module ("HLint: ignore Use infix"::String) #-}
{-# ANN module ("HLint: ignore Use mappend"::String) #-}
{-# ANN module ("HLint: ignore Use fmap"::String) #-}
{-# ANN module ("HLint: error Redundant $"::String) #-}
{-# ANN module ("HLint: ignore Use ."::String) #-}

But when I try to mark my package as Safe with

{-# LANGUAGE Safe #-}

I get

    • Annotations are not compatible with Safe Haskell.
      See https://ghc.haskell.org/trac/ghc/ticket/10826
    • In the annotation:
        {-# ANN module ("HLint: ignore Use ." :: String) #-}
   |
80 | {-# ANN module ("HLint: ignore Use ."::String) #-}
   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

while with the annotations removed, I can build and test as Safe without errors.

Is there an alternative way to customize Hlint that allows my package to be marked as Safe?

Answer 1

Instead of using ANN pragmas, you can use either:

{-# HLINT ignore "Use mappend" #-}

or:

{- HLINT ignore "Use mappend" -}

The former will trigger a warning from GHC about an unknown pragma.

See also:

https://github.com/ndmitchell/hlint#ignoring-hints