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.
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. Cheers, -- Pavel
