T7891 fails as '*** Core Lint errors : in result of Simplifier ***' in WAY=optasm

ghc-HEAD:

$ make fulltest TEST="T7891" WAY=optasm

cd ./typecheck/should_compile && '/home/slyfox/dev/git/ghc-validate/inplace/bin/ghc-stage2' -fforce-recomp -dcore-lint -dcmm-lint -dno-debug-output -no-user-package-db -rtsopts -fno-ghci-history -c T7891.hs -O -fasm  -fno-warn-incomplete-patterns >T7891.comp.stderr 2>&1
Compile failed (status 256) errors were:
*** Core Lint errors : in result of Simplifier ***
<no location info>: Warning:
    In the type ‘a_12 -> t_aiF -> t_aiF’
    @ a_12 is out of scope
*** Offending Program ***
T7891.tf :: T7891.T
[LclIdX,
 Arity=1,
 Str=DmdType,
 Unf=Unf{Src=<vanilla>, TopLvl=True, Value=True, ConLike=True,
         WorkFree=True, Expandable=True,
         Guidance=ALWAYS_IF(arity=0,unsat_ok=True,boring_ok=True)}]
T7891.tf =
  GHC.Base.id
  `cast` (Sym T7891.NTCo:T[0]
          :: (forall t_ahj. t_ahj -> t_ahj) ~R# T7891.T)

T7891.f :: forall t_ahw. t_ahw -> t_ahw
[LclIdX,
 Arity=1,
 Str=DmdType,
 Unf=Unf{Src=<vanilla>, TopLvl=True, Value=True, ConLike=True,
         WorkFree=True, Expandable=True,
         Guidance=ALWAYS_IF(arity=0,unsat_ok=True,boring_ok=True)}]
T7891.f =
  T7891.tf
  `cast` (T7891.NTCo:T[0]
          :: T7891.T ~R# (forall t_ahj. t_ahj -> t_ahj))
...

Trac metadata

Trac field	Value
Version	7.9
Type	Bug
TypeOfFailure	OtherFailure
Priority	normal
Resolution	Unresolved
Component	Compiler
Test case
Differential revisions
BlockedBy
Related
Blocking
CC	simonpj
Operating system
Architecture