Opened 6 years ago

Closed 6 years ago

#5192 closed bug (fixed)

the 'impossible' happened: hsValBindsImplicits: ValBindsIn

Reported by: CoreyOConnor Owned by: simonpj
Priority: normal Milestone:
Component: Compiler Version: 7.1
Keywords: Cc:
Operating System: Unknown/Multiple Architecture: Unknown/Multiple
Type of failure: GHC rejects valid program Test Case:
Blocked By: Blocking:
Related Tickets: Differential Rev(s):
Wiki Page:


Compiling regex-tdfa 1.1.7 using ghc 7.1.20110509 (commit 2d5205118357cac8a2dd43b33bcd93a3c00f5558) fails with:

[10 of 23] Compiling Text.Regex.TDFA.CorePattern ( Text/Regex/TDFA/CorePattern.hs, dist/build/Text/Regex/TDFA/CorePattern.o )
ghc: panic! (the 'impossible' happened)
  (GHC version 7.1.20110509 for i386-apple-darwin):
	hsValBindsImplicits: ValBindsIn

Please report this as a GHC bug:

Change History (4)

comment:1 Changed 6 years ago by simonpj

Owner: set to simonpj

I'm on this.

comment:2 Changed 6 years ago by simonpj

Status: newmerge

Thanks for identifying this. Fixed by

commit 10ffbfd2624f37d6d61ecb4b8d42f1463cc1d476
Author: Simon Peyton Jones <>
Date:   Thu May 12 11:01:34 2011 +0100

    Fix Trac #5192: missing case in hsValBindsImplicits
    This fixes the bug, adds some comments, and a tiny bit of refactoring


 compiler/hsSyn/HsBinds.lhs |   12 ++++++------
 compiler/hsSyn/HsUtils.lhs |   13 ++++++++-----
 2 files changed, 14 insertions(+), 11 deletions(-)

This should go into the 7.0.4 branch if possible, so I'll change to 'merge'.

comment:3 Changed 6 years ago by CoreyOConnor

regex-tdfa compiles as expected with HEAD now. Thanks!

comment:4 Changed 6 years ago by igloo

Resolution: fixed
Status: mergeclosed

This missed 7.0.4.

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