Standalone deriving Show at GHCi prompt causes divergence when printing

Deriving a show instance for a data type (defined either with the standard Haskell 98 syntax or with GADT syntax) within GHCi using the command:

instance Show <typename>

causes divergence/stack overflow when printing values of that type. The issue does not manifest itself when you use the standard deriving mechanism within a Haskell source file.

Minimum example necessary to replicate:

module Main (
  main
)
where

  -- At GHCi prompt type
  --   instance Show Bool'
  -- then
  --   True'
  -- to get a stack overflow
  data Bool'
    = True'
    | False'

  main = return ()

Trac metadata

Trac field	Value
Version	7.4.1
Type	Bug
TypeOfFailure	OtherFailure
Priority	normal
Resolution	Unresolved
Component	GHCi
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