Opened 12 years ago

Closed 12 years ago

Last modified 44 years ago

#59 closed bug (Fixed)

panic! simplCore/Simplify.lhs:1490

Reported by: mlauer Owned by: nobody
Priority: normal Milestone:
Component: Compiler Version: 5.02
Keywords: Cc:
Operating System: Architecture:
Type of failure: Difficulty:
Test Case: Blocked By:
Blocking: Related Tickets:

Description

When compiling the attached file you get the error
below. My System is SuSE Linux 7.2

prompt > ghc --version
The Glorious Glasgow Haskell Compilation System,
version 5.02.1

prompt > ghc -c A.hs
ghc-5.02.1: panic! (the `impossible' happened, GHC
version 5.02.1):
        simplCore/Simplify.lhs:1490: Non-exhaustive
patterns in function cat_evals


Please report it as a compiler bug to
glasgow-haskell-bugs@haskell.org,
or http://sourceforge.net/projects/ghc/.

Attachments (1)

A.3.hs (293 bytes) - added by mlauer 12 years ago.

Download all attachments as: .zip

Change History (2)

Changed 12 years ago by mlauer

comment:1 Changed 12 years ago by simonpj

  • Status changed from assigned to closed
Logged In: YES 
user_id=50165

The program is invalid, but the compiler should not crash.

It's invalid because in
  data M m t a = Monad m => M { unM::(m (S m t a))}
the existential context does not introduce any fresh type 
variables; m is already in scope.

I've added new validity checking to the HEAD compiler.  I 
doubt it's worth fixing in 5.02.2

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