diff options
Diffstat (limited to 'compiler')
-rw-r--r-- | compiler/typecheck/TcMType.lhs | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/compiler/typecheck/TcMType.lhs b/compiler/typecheck/TcMType.lhs index 9d74ff894a..74533340f3 100644 --- a/compiler/typecheck/TcMType.lhs +++ b/compiler/typecheck/TcMType.lhs @@ -364,8 +364,8 @@ writeMetaTyVarRef tyvar ref ty | otherwise = do { meta_details <- readMutVar ref; - ; WARN( not (isFlexi meta_details), - hang (text "Double update of meta tyvar") + ; ASSERT2( isFlexi meta_details, + hang (text "Double update of meta tyvar") 2 (ppr tyvar $$ ppr meta_details) ) traceTc "writeMetaTyVar" (ppr tyvar <+> text ":=" <+> ppr ty) |