threadDelay not ending

[Volker Stolz]

* Rich Fought <whatever at fsrz.net>:
> I've got some unit test code that forks off test processes using the 
> 'system' function and then delays using 'threadDelay' to synchronize 
> with the test process.
>
> This has worked fine until I upgraded to 6.4.2, now some of the 
> 'threadDelay' calls never return - it's like they are stuck in limbo.

You could build an RTS with debugging support to see what is going on.

Volker