On Thu, Jun 21, 2012 at 8:31 PM, Pavel Krivanek <pavel.krivanek@gmail.com> wrote:

Hi,

firstly a question: should SystemAnnouncements be part of the Pharo
Kernel? On one side it makes sense to have in there however we can
keep it unloadable. It seems that currently the only class in Pharo
Kernel that uses it is the PragmaCollector.

I think it is only a matter of time that you will need to include SystemAnnouncements in the system.
SystemChangeNotifier is slowly being replaced by SystemAnnouncer. So at some point you will HAVE to include it in Kernel.
So I guess you can already start including it :)

�

There is one issue related to SystemAnnouncements. As you may see from
this trace - https://ci.lille.inria.fr/pharo/view/Pharo-Kernel%202.0/job/Pharo%20Kernel%202.0/136/console
- it may happen that the announcements are sent to an obsolete class.
The SystemAnnouncemnets use weak bindings however the receiver becomes
obsolete, not nil.

I have seen similar problems. I was creating/removing (or something) with methods, and then I was removing the class (I was doing this on tests). The problem was that since the notifications were run in a fork, at the time RPackage tried to handle the event, the class was already obsolete and therefore there was an error...

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Cheers,
-- Pavel