New 3.9alpha image is ready! (sort of)

[Andreas Raab]

Hi Doug -

>>In Tweak we have basically a fixed load order (==configuration) which 
>>originates from the configuration used in the original build. But the 
>>main reason for wanting to have a well-defined load order is that 
>>typically, if there are sets of cross-package changes, they follow 
>>already established dependencies.
> 
> 
> Yes, makes sense.  That should reduce the need for special update
> changesets to load packages in a special order.

Yes. That's another implicit advantage - most of the time stuff just 
"works" by loading the latest package versions.

> Any suggestions on how I should implement this?  I guess we could just
> have a method defined somewhere (in the load-updates code) which has a
> hardcoded, ordered list of the 35 package names.  I guess this list
> won't change very often.  (The 3.9a-6676 image doesn't seem to be
> hanging onto the MCConfiguration instance that was loaded in update
> #6676, otherwise I might try to use that.)

What we've done so far is to have a global which stores the latest 
version of a configuration and then just works issuing a 
"updateFromRepositories". It's very simple stuff - if you are curious 
check out CProjectBuilder>>loadUpdates and updateFromRepositories.

>>Meaning that if I change a base class 
>>to include a new property and then some higher-level code to use it the 
>>load-order simply ensures that by default we load the dependent package 
>>version first.
> 
> The first half of your sentence makes it sound like the
> prerequisite/base packages (e.g. Kernel) should be loaded first, which I
> think sounds right.  Then the outer ("dependent") packages later, not
> earlier, right?  ("dependent" is the opposite of "prerequisite" AFAIK.)

Yes.

Cheers,
   - Andreas