For those interested in shrinking Trunk, this is the job Pavel's set
up to shrink Pharo:
https://ci.inria.fr/pharo-contribution/view/Pharo-Kernel-3.0/job/PharoKernel3.0-FromTopShrink/

The meat is the script itself:
https://ci.inria.fr/pharo-contribution/view/Pharo-Kernel-3.0/job/PharoKernel3.0-FromTopShrink/lastSuccessfulBuild/artifact/shrink.st

I'm mentioning it here because (a) other folk than just myself are
interested in this work and (b) I haven't had a chance to digest the
script.

frank