Type error reported in wrong place with repeated type family expressions

When I say

{-# LANGUAGE TypeFamilies #-}

type family F x
type instance F Int = Bool

foo :: F Int -> ()
foo True = ()

bar :: F Int -> ()
bar 'x' = ()

I get

/Users/rae/temp/Bug.hs:7:5:
    Couldn't match type ‘Char’ with ‘Bool’
    Expected type: F Int
      Actual type: Bool
    In the pattern: True
    In an equation for ‘foo’: foo True = ()

/Users/rae/temp/Bug.hs:10:5:
    Couldn't match type ‘Bool’ with ‘Char’
    Expected type: F Int
      Actual type: Char
    In the pattern: 'x'
    In an equation for ‘bar’: bar 'x' = ()

The second error is most certainly correct, but the first one is most certainly not. Note that the first error is reported on the definition of foo, which should type-check. Also, the "Couldn't match ..." bit doesn't correspond at all with the expected/actual bit. And, the expected/actual bit shows two types that are in fact equal.

This behavior can be seen in HEAD (as of Jul. 2), 7.8.3, and 7.8.2. This is a regression from 7.6.3, where this behavior does not appear.

Trac metadata

Trac field	Value
Version	7.8.3
Type	Bug
TypeOfFailure	OtherFailure
Priority	normal
Resolution	Unresolved
Component	Compiler (Type checker)
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