Snappy and Dependency Tracking

[robert_joslyn at selinc.com]

> A snapcraft "part" is like a "source code package", and you
> can say "build this part after you built those other parts".

The basic parts structure works fine, but it just doesn't scale well since 
it requires me to manually figure out my entire dependency graph. 
Maintaining a project that has dozens (or more) parts will be problematic 
without some automated mechanism to help deal with the dependency chain.

> So you'll be able to define a part of your own that depends on
> having some other parts around before yours gets built, and you
> can specify that just by listing those other parts in the "after"
> section of your part definition. Snapcraft will go and fetch
> those part definitions from the "cloud" (a.k.a. wiki page :)) and
> build them as if you had copied their part definitions into your
> own snapcraft.

This is more interesting and should make it much easier to manage. After 
looking at the Snapcraft code again, it looks like the initial 
implementation of this is already in place. As a first glance, I think the 
only thing missing for me is the ability to set the URL where Snapcraft 
looks (but I can deal with that locally for now). I'll play with this a 
bit and see how it works for me.

Thanks!

--
Robert Joslyn
Software Engineer, R&D - Automation
Schweitzer Engineering Laboratories
509-332-1890 ext. 3214