> > Well I wasn't aware of that (though I'm running current rather than 1.6).  
> > Where's the relevant PR?
> 
> When I mumbled on ICB about hangs, I immediately got the advice to compile
> without strongarm optimization, that's why I assumed it was generally known.

Ah, yes, that ICB thing.  Don't have time to do that...

> 
> I opened a PR: port-shark/20027

So I noticed.  Ta.

> > If it's a random behaviour, then my 
> > first suspicion would be that it's some sort of timing issue (or cache 
> > related).  Compiler errors generally lead to repeatable problems.  There 
> > was a lot of hacking on the pmap in the run up to 1.6, and it wouldn't 
> > surprise me in the least if that wasn't the cause of your problems.
> 
> So changing the optimization just changes timing in a way that the bug is 
> hidden? Yes, I think this is possible.
> 

Certainly that's possible.  I'm not going to go out on a limb and say it's 
the only possible cause though... I'm pretty certain that there is at 
least one bug somewhere in the compiler, which is revealed every time you 
try to run Xemacs, but since it doesn't cause a crash, and since debugging 
X libraries is so hard (and I've no idea where in the towering edifice the 
problem lies) I haven't been able to track that one down.

R.