errorOn :: Outputable a => LocatedA a -> String -> b
errorOn (L pos val) msg = exitMessageImpure $
    showSrcSpan (locA pos) ++
    ": Error while reading hint file, " ++ msg ++ "\n" ++
    unsafePrettyPrint val
errorOn :: Outputable a => LocatedA a -> String -> b
errorOn (L pos val) msg = exitMessageImpure $
    showSrcSpan (locA pos) ++
    ": Error while reading hint file, " ++ msg ++ "\n" ++
    unsafePrettyPrint val
errorOn (L pos val) msg = exitMessageImpure $
    showSrcSpan (locA pos) ++
    ": Error while reading hint file, " ++ msg ++ "\n" ++
    unsafePrettyPrint val