Opened 8 years ago

Closed 8 years ago

Last modified 8 years ago

#5643 closed bug (fixed)

New constraint solver: emitWantecCts

Reported by: simonpj Owned by: dimitris
Priority: normal Milestone: 7.4.1
Component: Compiler Version: 7.2.1
Keywords: Cc:
Operating System: Unknown/Multiple Architecture: Unknown/Multiple
Type of failure: None/Unknown Test Case: typecheck/should_compile/T5643
Blocked By: Blocking:
Related Tickets: Differential Rev(s):
Wiki Page:


David T says: I'm getting a panic when trying to build the listlike package with ghc HEAD on Mac OSX 10.7, using a 64bit build of ghc.

Building ListLike-3.1.2...
[1 of 8] Compiling Data.ListLike.FoldableLL ( src/Data/ListLike/FoldableLL.hs, dist/build/Data/ListLike/FoldableLL.o
[2 of 8] Compiling Data.ListLike.Base ( src/Data/ListLike/Base.hs, dist/build/Data/ListLike/Base.o )
ghc: panic! (the 'impossible' happened)
  (GHC version 7.3.20111117 for x86_64-apple-darwin):
	emitWantecCts: can't emit non-wanted!

Change History (5)

comment:1 Changed 8 years ago by simonpj

Owner: set to dimitris

comment:2 Changed 8 years ago by simonpj

Fixed by

commit 24d630a804d263184974afae65ffb3031a9cd13a
Author: Dimitrios Vytiniotis <>
Date:   Thu Nov 17 16:39:54 2011 +0000

    Fix panic (missing keepWanteds) in simplifyApprox

 compiler/typecheck/TcSimplify.lhs |   24 ++++++------------------
 1 files changed, 6 insertions(+), 18 deletions(-)

Dimitrios is thinking about a test case


comment:3 Changed 8 years ago by igloo

Milestone: 7.4.1

comment:4 Changed 8 years ago by dimitris

Resolution: fixed
Status: newclosed

Just pushed test case in testsuite (typecheck/should_compile/T5643.hs).

comment:5 Changed 8 years ago by simonpj

Test Case: typecheck/should_compile/T5643
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