For some reason CompiledBlock>>selector was not installed during the
update. When I browsed the changes between my image and
Kernel-eem.1319, it sat right there.

Am Sa., 28. März 2020 um 10:54 Uhr schrieb Jakob Reschke
<forums.jakob at resfarm.de>:
>
> Hello,
>
> I'd like to share my experience updating a Trunk image from
> just-before-the-release to today's version. Maybe some of the points are
> important outside of my box.
>
> First, the setting of the primary bytecode encoder was thwarted by one
> single method in the Scorch tests. I had Scorch loaded because it was
> my test subject for Tonel repositories. The setter method therefore
> complained that both encoders were already in use (I don't remember the
> exact message).
>
> So I tried to unload Scorch (package "Scorching" and associated). That
> removed some important methods from my image, which left many of the
> tools broken, including the debugger. The reason is that Scorching put
> some method overrides in Context, but they were not in the category
> *Scorcing-override, but just *Scorching. That's why they were removed
> on unload. So I went to my loaded Kernel Monticello version and
> restored the overridden methods from there, then unloaded Scorch. That
> worked.
>
> After that, the Squeak update succeeded.
>
> But now I get a SubclassResponsiblity exception when #selector is sent
> to a CompiledBlock in MorphicDebugger(Debugger)>>messageIconAt:. Now
> going on to try debug this... It's hard because the image freezes
> rather quickly, and needs much time until the user interrupt appers.
> Move the pointer over a wrong spot and you get a hand full of new
> debugger windows or the next freeze... First step: disabling the Show
> message icons preference.
>
> Kind regards,
> Jakob