Partial type signatures generate typed hole warnings

GHCi generates typed hole warnings in type signatures even when PartialTypeSignatures is enabled:

> :set -XPartialTypeSignatures 

> :t (==) :: Char -> _
<interactive>:1:17: Warning:
    Found hole ‘_’ with type: Char -> Bool
    In an expression type signature: Char -> _
    In the expression: (==) :: Char -> _
(==) :: Char -> _ :: Char -> Char -> Bool

> :set -XNoPartialTypeSignatures

> :t (==) :: Char -> _
<interactive>:1:17:
    Found hole ‘_’ with type: Char -> Bool
    To use the inferred type, enable PartialTypeSignatures
    In an expression type signature: Char -> _
    In the expression: (==) :: Char -> _

Similarly, GHC 7.10.1, when given the following source,

{-# LANGUAGE PartialTypeSignatures #-}

f = (==) :: Char -> _

main = return ()

mentions that it "found a hole".

Trac metadata

Trac field	Value
Version	7.10.1
Type	Bug
TypeOfFailure	OtherFailure
Priority	normal
Resolution	Unresolved
Component	Compiler
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