Core Lint error on empty case

This module:

{-# LANGUAGE EmptyCase #-}
module Bug where

data Void

absurd :: Void -> a
absurd v = case v of {}

data Foo = Foo !Void

absurdFoo :: Foo -> a
absurdFoo (Foo x) = absurd x

Compiled using ghc-8.2.0.20170704 -O -dcore-lint Bug.hs

Gives the following error:

[1 of 1] Compiling Bug              ( Bug.hs, Bug.o )
*** Core Lint errors : in result of Simplifier ***
<no location info>: warning:
    In a case alternative: (Foo x_ap6 :: Void)
    No alternatives for a case scrutinee in head-normal form: x_ap6
*** Offending Program ***
absurd :: forall a. Void -> a
[LclIdX,
 Arity=1,
 Unf=Unf{Src=<vanilla>, TopLvl=True, Value=True, ConLike=True,
         WorkFree=True, Expandable=True,
         Guidance=ALWAYS_IF(arity=1,unsat_ok=True,boring_ok=True)}]
absurd = \ (@ a_apU) (v_ap5 :: Void) -> case v_ap5 of { }

absurdFoo :: forall a. Foo -> a
[LclIdX,
 Arity=1,
 Unf=Unf{Src=<vanilla>, TopLvl=True, Value=True, ConLike=True,
         WorkFree=True, Expandable=True,
         Guidance=ALWAYS_IF(arity=1,unsat_ok=True,boring_ok=True)}]
absurdFoo
  = \ (@ a_apY) (ds_dUn :: Foo) ->
      case ds_dUn of { Foo x_ap6 -> case x_ap6 of { } }

-- irrelevant stuff omitted

When I manually inline absurd or remove the strictness annotation on Foo, the error goes away.

Trac metadata

Trac field	Value
Version	8.2.1-rc3
Type	Bug
TypeOfFailure	OtherFailure
Priority	normal
Resolution	Unresolved
Component	Compiler
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