Hi all,
again a good and difficult to analyze contribution.
We mostly send runSimulated:contextAtEachStep: to thisContext, except
in one case in base image:

    MessageTally tallySends: [3.14159 printString]

This is effectively broken in trunk, and repaired after applying Kernel-ct.1363.
Before I merge this, additional advice is welcome, this is a tough
subject, breaking the Debugger would be the last thing we want to do.