[Haskell-cafe] Re: GHC 6.7 on Windows / containers-0.1 package?

Peter Hercek peter at syncad.com
Thu Sep 20 04:32:00 EDT 2007

Stefan O'Rear wrote:
> You said 0% CPU.  That's *very* important.  It means that you are using
> the threaded runtime (GHCi?), and that you triggered a blackhole.  You
> should be able to handle this by compiling your program with -prof (do
> *not* use -threaded!), and running with +RTS -xc.  With luck, that will
> give you a backtrace to the infinite loop.
> PS. blackholes are a serious dark corner of GHC's execution model,
> chances are better than even that if you try to use the debugger for
> this you will discover a new and (for you) crippling bug.  I wouldn't
> recommend it.

Hi Stefan,

I do not understand. Do you mean you would not recommend to try the debugger
  to check this problem?

I had something which looked similar but the problem was that my gui (gkt2hs)
application is also printing to console and there was an active selection
in the console, so the printing was suspended :-)


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