`Strict` causes core lint error

$ ghci -dcore-lint -XStrict -XGADTs -XRankNTypes -XTypeApplications -XScopedTypeVariables -ignore-dot-ghci 
GHCi, version 8.1.20160117: http://www.haskell.org/ghc/  :? for help
Prelude> import Data.Typeable
Prelude Data.Typeable> let zero :: forall x. Typeable x => Maybe x; zero = do Refl <- eqT @Int @x; pure 0
Prelude Data.Typeable> zero
*** Core Lint errors : in result of desugar expression ***
<no location info>: warning:
    In the expression: ds_d1t9
                         @ x_a1sx $dTypeable_a1sC @ x_a1sx $dTypeable_a1sz
    $dTypeable_a1sz :: Typeable x_a1sx
    [LclId, Str=DmdType] is out of scope
*** Offending Program ***
let {
  $dTypeable_a1sS :: Typeable ()
  [LclId, Str=DmdType]
  $dTypeable_a1sS =
    D:Typeable
      @ *
      @ ()
      (let {
         ds_d1tb :: TypeRep
         [LclId, Str=DmdType]
         ds_d1tb = mkPolyTyConApp $tc() ([] @ TypeRep) ([] @ TypeRep) } in
       \ (wild_00 :: Proxy# ()) -> ds_d1tb) } in
let {
  $dShow_a1sU :: Show ()
  [LclId, Str=DmdType]
  $dShow_a1sU = $fShow() } in
let {
  $dShow_a1sP :: Show (Maybe ())
  [LclId, Str=DmdType]
  $dShow_a1sP = $fShowMaybe @ () $dShow_a1sU } in
letrec {
  ds_d1t9
    :: forall x_a1sx.
       Typeable x_a1sx =>
       forall x_a11P. Typeable x_a11P => Maybe x_a11P
  [LclId, Str=DmdType]
  ds_d1t9 =
    \ (@ x_a1sx) ($dTypeable_a1sC :: Typeable x_a1sx) ->
      let {
        $dTypeable_a1sz :: Typeable x_a1sx
        [LclId, Str=DmdType]
        $dTypeable_a1sz = $dTypeable_a1sC } in
      letrec {
        it_a1sw :: forall x_a11P. Typeable x_a11P => Maybe x_a11P
        [LclId, Str=DmdType]
        it_a1sw = zero; } in
      it_a1sw;
  it_a1dz :: forall x_a1sx. Typeable x_a1sx => Maybe x_a1sx
  [LclId, Str=DmdType]
  it_a1dz =
    \ (@ x_a1sx) ($dTypeable_a1sC :: Typeable x_a1sx) ->
      ds_d1t9 @ x_a1sx $dTypeable_a1sC @ x_a1sx $dTypeable_a1sz; } in
case it_a1dz of it_a1dz { __DEFAULT ->
thenIO
  @ ()
  @ [()]
  (print @ (Maybe ()) $dShow_a1sP (it_a1dz @ () $dTypeable_a1sS))
  (returnIO
     @ [()]
     (: @ ()
        (unsafeCoerce#
           @ 'Lifted
           @ 'Lifted
           @ (forall x_a1sx. Typeable x_a1sx => Maybe x_a1sx)
           @ ()
           it_a1dz)
        ([] @ ())))
}
*** End of Offense ***


<no location info>: error: 
Compilation had errors


*** Exception: ExitFailure 1
Prelude Data.Typeable> 

Trac metadata

Trac field	Value
Version	8.1
Type	Bug
TypeOfFailure	OtherFailure
Priority	normal
Resolution	Unresolved
Component	Compiler
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