rg :: (String -> DynFlags -> DynFlags) -> OptKind (CmdLineP DynFlags)
hasArg fn = HasArg (upd . fn)

ha
hasArg :: (String -> DynFlags -> DynFlags) -> OptKind (CmdLineP DynFlags)
hasArg fn = HasArg (upd . fn)
hasArg fn = HasArg (upd . fn)