Fix Trac #3011 by temporarily making it only a WARN if we assign twice
to the same unification variable.
= ASSERT( isMetaTyVar tyvar )
-- TOM: It should also work for coercions
-- ASSERT2( k2 `isSubKind` k1, (ppr tyvar <+> ppr k1) $$ (ppr ty <+> ppr k2) )
= ASSERT( isMetaTyVar tyvar )
-- TOM: It should also work for coercions
-- ASSERT2( k2 `isSubKind` k1, (ppr tyvar <+> ppr k1) $$ (ppr ty <+> ppr k2) )
- do { ASSERTM2( do { details <- readMetaTyVar tyvar; return (isFlexi details) }, ppr tyvar )
+ do { if debugIsOn then do { details <- readMetaTyVar tyvar;
+ ; WARN( not (isFlexi details), ppr tyvar )
+ return () }
+ else return ()
+ -- Temporarily make this a warning, until we fix Trac #2999
+
; traceTc (text "writeMetaTyVar" <+> ppr tyvar <+> text ":=" <+> ppr ty)
; writeMutVar (metaTvRef tyvar) (Indirect ty) }
where
; traceTc (text "writeMetaTyVar" <+> ppr tyvar <+> text ":=" <+> ppr ty)
; writeMutVar (metaTvRef tyvar) (Indirect ty) }
where