diff options
| -rw-r--r-- | compiler/GHC/Core/Subst.hs | 9 |
1 files changed, 5 insertions, 4 deletions
diff --git a/compiler/GHC/Core/Subst.hs b/compiler/GHC/Core/Subst.hs index d062227a9b..1c7d138574 100644 --- a/compiler/GHC/Core/Subst.hs +++ b/compiler/GHC/Core/Subst.hs @@ -66,6 +66,7 @@ import GHC.Utils.Misc import GHC.Utils.Outputable import GHC.Utils.Panic import Data.List (mapAccumL) +import GHC.Driver.Ppr @@ -253,10 +254,10 @@ lookupIdSubst (Subst in_scope ids _ _) v | not (isLocalId v) = Var v | Just e <- lookupVarEnv ids v = e | Just v' <- lookupInScope in_scope v = Var v' - -- Vital! See Note [Extending the Subst] - -- If v isn't in the InScopeSet, we panic, because - -- it's a bad bug and we reallly want to know - | otherwise = pprPanic "lookupIdSubst" (ppr v $$ ppr in_scope) + + | otherwise = WARN( True, text "GHC.Core.Subst.lookupIdSubst" <+> ppr v + $$ ppr in_scope) + Var v -- | Find the substitution for a 'TyVar' in the 'Subst' lookupTCvSubst :: Subst -> TyVar -> Type |