Deriving Show for Word#

{-# LANGUAGE MagicHash #-}
import GHC.Prim
data A = A Word# deriving Show

This works in 7.6.3, but 7.7 gives

    Can't find interface-file declaration for data constructor GHC.Types.W#
      Probable cause: bug in .hi-boot file, or inconsistent .hi file
      Use -ddump-if-trace to get an idea of which file caused the error

The same file works if Word# is replaced by Int#.

Trac metadata

Trac field	Value
Version	7.6.3
Type	Bug
TypeOfFailure	OtherFailure
Priority	normal
Resolution	Unresolved
Component	Compiler
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