Type error message pretty-prints unboxed tuples wrongly

I get

PASysDep.hs:51:
    Couldn't match
	`(State# s, MutableByteArray# s)'
	against
	`(State# t, MutableByteArray# t)'
	Expected type: (State# s, MutableByteArray# s)
	Inferred type: (State# t, MutableByteArray# t)
    In the application `newByteArray# (wORD_SCALE n#) s#'
    In the right-hand side of an equation for `newIntArray#':
	newByteArray# (wORD_SCALE n#) s#

where the actual error is that I have used boxed instead of unboxed tuples in a type signature.  In other words, the inferred type should have been reported as

  (# State# t, MutableByteArray# t #)

The code producing this error is as follows:

import PrelByteArr (cHAR_SCALE, wORD_SCALE, fLOAT_SCALE, dOUBLE_SCALE)
import PrelGHC

newIntArray# :: Int# -> State# s -> (State# s, MutableByteArray# s)
newIntArray# n# s# = newByteArray# (wORD_SCALE n#) s#

Trac metadata

Trac field	Value
Version	None
Type	Bug
TypeOfFailure	OtherFailure
Priority	normal
Resolution	ResolvedFixed
Component	Compiler (Type checker)
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