From 9524fc33fdd65eca2c29be0dd03904fae4b22f46 Mon Sep 17 00:00:00 2001 From: "simonpj@microsoft.com" Date: Wed, 4 Feb 2009 08:38:00 +0000 Subject: [PATCH] Fix Trac #2999: change an ASSERT to a WARN A bug in the constraint simplifier means that an equality can be solved twice. It's harmless, and will go away with the new constraint simplifier. Hence warning, to avoid unnecessary outright failure on eg Trac #2999. --- compiler/typecheck/TcTyFuns.lhs | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-) diff --git a/compiler/typecheck/TcTyFuns.lhs b/compiler/typecheck/TcTyFuns.lhs index 0066d2f..5777955 100644 --- a/compiler/typecheck/TcTyFuns.lhs +++ b/compiler/typecheck/TcTyFuns.lhs @@ -37,6 +37,7 @@ import Name import Bag import Outputable import SrcLoc ( Located(..) ) +import Util ( debugIsOn ) import Maybes import FastString @@ -278,7 +279,15 @@ no further propoagation is possible. -- normaliseEqs :: [Inst] -> TcM EqConfig normaliseEqs eqs - = do { ASSERTM2( allM wantedEqInstIsUnsolved eqs, ppr eqs ) + = do { if debugIsOn then do { all_unsolved <- allM wantedEqInstIsUnsolved eqs + ; let msg = ptext (sLit "(This warning is harmless; for Simon & Manuel)") + ; WARN( not all_unsolved, msg $$ ppr eqs ) return () } + else return () + -- This is just a warning (not an error) because a current + -- harmless bug means that we sometimes solve the same + -- equality more than once It'll go away with the new + -- solver. See Trac #2999 for example + ; traceTc $ ptext (sLit "Entering normaliseEqs") ; (eqss, skolemss) <- mapAndUnzipM normEqInst eqs -- 1.7.10.4