Posted by Blair McGlashan on Nov 23, 2000; 6:26pm
URL: https://forum.world.st/4-0-some-possible-problems-tp3358241p3358263.html

Bill

> > Perhaps more serious, I've noticed a few strange things in the debugger.
> > The first sign of it was that a block temporary wasn't inspectable
> (unknown
> > symbol) when I felt it should have been; another temp was known but the
> > value was nil which clearly wasn't correct.  I've since seen a few cases
> in
> > which a variable is nil in one frame (walkback line anyway - hope I'm
not
> > abusing terminology here) and has the correct value in the one above or
> > below it.
>
> One caveat: I was debugging Migrate's progress-dialog loop at the time.  I
> haven't yet noticed this kind of thing outside of progress loops.

I believe it is a long standing issue that the Debugger isn't able to cope
correctly with blocks homed in another process (the progress dialog forks a
process to run the monitored operation), as it assumes that everything is in
one process. This is on the list for fixing, but hasn't been a terribly high
priority because it is not often a problem in practice - in fact debugging
stuff at the base of progress dialog loops is the only case I ever come
across it, and what I usually do (as a workaround) is to arrange the code so
that I can debug the code without the progress dialog - a DeafObject
suffices for the target of the progress notifications.

I'd be interested to know if you think the problem is more severe or
different to 3.0.

Regards

Blair