ANNOUNCE: GHC 6.10.2 Release Candidate 1

jutaro jnf at
Thu Mar 19 16:43:26 EDT 2009

Hello Simon,
I've put a request about the issue on the gtk2hs users mailing list:

> I've tried a gtk2hs app on ghc 6.10.2 release candidate.
> It crashes frequently and Simon (as you can read down here) assumes it
> is gtk2hs problem.
> My question is:
>        Is this problem known to gtk2hs developers?
>        Is it really a gtk2hs problem?
>        How difficult is it to fix the problem?
>        When will we have a patch to use gtk2hs with 6.10.2, 
>                is it already in the repo?      

However, I'm a little surprised that a little version upgrade from 6.10.1 to
6.10.2 may break all gui apps based on gtk2hs. May it be that many more apps
are affected because of this change? What's about wxhaskell e.g.? Well,
maybe we have only few Haskell applications around, but usually I
wouldn't expect such a dramatic effect from such a moderate upgrade. Is this
fix so important to introduce it now? What does it help when it was never
officially supported if it causes such troubles?


Simon Marlow-7 wrote:
> jutaro wrote:
>> I've installed a GUI application based on gtk2hs.
>> It frequently crashes with the error: 
>> leksah: error: a C finalizer called back into Haskell.
>> use Foreign.Concurrent.newForeignPtr for Haskell finalizers.
>> This error did never occur with the 6.10 released version. It was
>> verified
>> that this happens on different machines. I've no idea how to isolate this
>> bug.
> This will need to be fixed in gtk2hs.  Previously GHC allowed finalizers
> to 
> call back into Haskell, but this was never officially supported.  Now it
> is 
> officially unsupported, because finalizers created via
> Foreign.mkForeignPtr 
> are run directly by the garbage collector.
> See
> Cheers,
> 	Simon
> _______________________________________________
> Glasgow-haskell-users mailing list
> Glasgow-haskell-users at

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