Building BuildStream with BuildStream (dog-fooding)

[Laurence Urhegyi <Laurence Urhegyi codethink co uk>]

Hi,

I'd like to start a discussion about dog-fooding with BuildStream. I think there 
are some clear benefits to this:

* Demonstrate confidence in BuildStream.
* Increase the amount of real world use cases, thus identifying more bugs.
* Mitigating against the risk of developers working 'in a vacuum', by ensuring 
developers are also users of the tool.

There is a risk that this will prove more difficult than anticipated, and 
potentially serve as a distraction that does not bring as much benefit as 
desired, but I think this risk is quite low, overall.

Anyway, there are people involved in the project who are much more informed on 
the matter than I. So far, having spoken to people informally about this, there 
seems to be a general consensus that this is clearly a good idea, but 
BuildStream is probably not yet ready for it. I welcome all thoughts on this. Is 
anything currently blocking it from happening that you know of? I have also 
opened up a gitlab ticket for this:

https://gitlab.com/BuildStream/buildstream/issues/410

Thanks,
Laurence