Replying by email since Trac is down. I nailed this one. This diff fixes it. It was a missing 'runFlatten'. However I propose not to commit a fix, because Richard's D653 refactors all that code and, I'm 99% certain, fixes the bug in a better way. I would like D653 to land though. Richard are you doing that, or are you waiting for Austin to? Simon Modified compiler/typecheck/TcInteract.hs diff --git a/compiler/typecheck/TcInteract.hs b/compiler/typecheck/TcInteract.hs index e83709c..4d4b31c 100644 --- a/compiler/typecheck/TcInteract.hs +++ b/compiler/typecheck/TcInteract.hs @@ -1420,6 +1420,7 @@ shortCutReduction old_ev fsk ax_co fam_tc tc_args | otherwise = ASSERT( not (isDerived old_ev) ) -- Caller ensures this ASSERT( ctEvEqRel old_ev == NomEq ) + runFlatten $ do { (xis, cos) <- flattenManyNom old_ev tc_args -- ax_co :: F args ~ G tc_args -- cos :: xis ~ tc_args | -----Original Message----- | From: ghc-tickets [mailto:ghc-tickets-bounces@haskell.org] On Behalf Of | GHC | Sent: 14 March 2015 03:07 | Cc: ghc-tickets@haskell.org | Subject: Re: [GHC] #10158: Panic compiling singletons: StgCmmEnv: | variable not found | | #10158: Panic compiling singletons: StgCmmEnv: variable not found | -------------------------------------+----------------------------------- | -- | Reporter: trommler | Owner: | Type: bug | Status: new | Priority: highest | Milestone: | Component: Compiler | Version: 7.11 | (CodeGen) | Keywords: | Resolution: | Architecture: | Operating System: Unknown/Multiple | Unknown/Multiple | Type of failure: None/Unknown | Test Case: | Blocked By: | Blocking: | Related Tickets: | Differential Revisions: | -------------------------------------+----------------------------------- | -- | Changes (by goldfire): | | * priority: normal => highest | | | Comment: | | Yikes! I hope I'm not overstating the importance of my library to GHC, | but | this sounds serious. | | Is this reproducible on the 7.10 branch? If so, please set the milestone | to 7.10.1. | | -- | Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/10158#comment:1 | GHC http://www.haskell.org/ghc/ | The Glasgow Haskell Compiler | _______________________________________________ | ghc-tickets mailing list | ghc-tickets@haskell.org | http://mail.haskell.org/cgi-bin/mailman/listinfo/ghc-tickets