Hi All,
finally the Spur Squeak trunk image is updateable. The image in http://www.mirandabanda.org/files/Cog/SpurImages/2014-10-16/ was created today and thanks to Bert Freudenberg's latest Monticello work can be updated independently of the non-Spur trunk. Spur VMs are available in http://www.mirandabanda.org/files/Cog/VM/VM.r3105/ (and later as they appear). Without wanting to appear too overconfident the Spur system looks to be ready for use apart from image segments (which I hope to have working some time next month). I'm really interested in having this stress tested by as many people as possible. Spur really does offer a significant performance and functionality improvement over the current system, but it needs testing to ensure its reliability.
Esteban Lorenzano is hard at work on the Pharo bootstrap for Spur so I hope Pharo 4 Spur will be available soon.
As far as trunk goes, using Spur alongside non-Spur trunk is going to be difficult to manage for the near future. Right now, Spur modifies the Collections, Compiler, Kernel and System packages, and this is done by auto-editing the non-Spur versions of those packages, something I do periodically as new versions arrive. I also auto-edit trunk configurations (the part of the image update scheme that ensures packages are loaded in the right order when there are dependencies between packages) from non-Spur "update" to Spur "update.spur" forms. This at east means that Spur can keep up with trunk. But it does /not/ provide a way of committing to Collections.spur, Compiler.spur, Kernel.spur or System.spur without getting out of sync with non-Spur trunk. Note that apart from these packages, one /can/ safely commit any other package from a Spur image to trunk.
Right now the plan is to release both V3 (the pre-Spur format) and Spur versions of Squeak 4.6 (I hope it'll be called Squeak 5.0). This isn't my preference. I'd like to see just Spur released, once reliability is verified. But I understand the safety and backward-compatibility concerns (Spur won't be able to load V3 image segments, and vice verse). The issue is of course that we have this tricky package situation to manage where, to keep the two systems in sync, modifications to Collections, Compiler, Kernel and System need to be committed from V3 and auto-edited to Spur. I think that's too clumsy to be practicable. Perhaps allowing the two systems to fork and doing a manual merge will be acceptable, but it'll be work to keep them in sync.