[Vm-dev] Help/advice tracking down a squeak-vm regression

Alex Bradbury asb at asbradbury.org
Sat May 5 16:53:24 UTC 2012

Hi all,

As some of you may know, MIT Scratch does not work on the latest
squeak-vm (4.4.7-2353). This is unfortunate, because that's the
version of squeak-vm packaged in Debian wheezy and thanks to the
recent GPLv2 relicensing of Scratch this incompatibility is the only
thing preventing Scratch from getting in to Debian's package archive
before the 'freeze' for the next version version (wheezy).

Miriam Ruiz and others have done some debugging at
<http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=471927>. The
symptoms are that when opening the Scratch image, you just get a black
window and 100% CPU usage. See Miriam's posts for straces and the
section of code that loops forever. In a situation like this, I'd
normally just do a binary search through the changes between the
working 4.0.3 and broken 4.4.7 using git bisect. However, given that
the VM code is automatically generated by VMM (is the Slang source
even version controlled?) I can't see an easy way to do that.

I'd really appreciate any help anyone can offer in debugging this issue,

Many thanks,


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