Fork can be used to avoid freezing issues unless of course they are caused by the VM. VM usually prefer to crash.
I have used fork once to load a very glitchy package when StHub was misbeheaving.
You do not need a spinner in this case because you can keep using the image. But if you want to find out if the process indeed has frozen in that case I can see its need.
is there an easy was to do some thing that is constantly changing? so if my image freezes (to export a 1gb ston file for example) I can see when it���s done.�� �� Or maybe there is a way to send a mac notification from Pharo?