stage3 build failing with core-lint error

Sometime around 10 March 2011, the nightly build on x86-64/Linux began failing the stage3 build with the following core-lint error:

*** Core Lint errors : in result of CorePrep ***
<no location info>:
    [RHS of ds4_s1PqX :: (FastString.FastString,
                          FastString.FastString)]
    Occurrence of a dead Id wild3_s1S4x
*** Offending Program ***
notHappyAtAll_r3z1 :: forall t_a5OH. t_a5OH
[GblId, Str=DmdType b]
notHappyAtAll_r3z1 =
  \ (@ t_a5OH) ->
    case GHC.Base.unpackCString# "Internal Happy error"
    of sat_s1Q0Y { __DEFAULT ->
    GHC.Err.error @ t_a5OH sat_s1Q0Y
    }

etc.

while building compiler/stage3/build/Parser.hs.

Trac metadata

Trac field	Value
Version	7.1
Type	Bug
TypeOfFailure	OtherFailure
Priority	highest
Resolution	Unresolved
Component	Compiler
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