[GHC] #10158: Panic compiling singletons: StgCmmEnv: variable not found

[Simon Peyton Jones]

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 at haskell.org] On Behalf Of
| GHC
| Sent: 14 March 2015 03:07
| Cc: ghc-tickets at 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 at haskell.org
| http://mail.haskell.org/cgi-bin/mailman/listinfo/ghc-tickets