Precedence errors are reported for undefined operators

I found a misleading error message.

If I add the import for (<$>), but I forget to save the file

-- other imports
-- import Control.Applicative ((<$>))
main = print $ (+1).(+2) <$> Just 5

I get the error

    precedence parsing error
        cannot mix `(.)' [infixr 9] and `(<$>)' [infixl 9] in the same infix expression

which is rather hard to debug, since it makes it seem that the problem is either with Control.Applicative's precedence definitions or that I've somehow imported (<$>) with a different precedence from somewhere else.

It would be nice if it would report instead that (<$>) wasn't defined yet.

Trac metadata

Trac field	Value
Version	6.10.1
Type	FeatureRequest
TypeOfFailure	OtherFailure
Priority	normal
Resolution	Unresolved
Component	Compiler
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