Trigger snap builds from PPAs

[Michał Sawicz]

It would be helpful if snap recipe builds could be triggered by new PPA binaries.

Related: bug #1638333

From IRC:
[13:30:30] <Saviq> cjwatson: hey, was it ever discussed to allow PPA builds to trigger snap recipes?
[13:30:58] <cjwatson> Saviq: not that I recall
[13:36:27] <Saviq> think that would be worth it / interesting?
[13:36:53] -*- Saviq files a wishlist bug
[13:36:57] <cjwatson> Saviq: possibly; I think it would require considerably better manifest knowledge than we currently have
[13:37:10] <cjwatson> i.e. we'd really IMO need to pick out which particular packages from a given archive affect the snap
[13:38:10] <Saviq> true
[13:40:29] <Saviq> hmm bug #1638333
[13:40:29] <ubot5> bug 1638333 in Launchpad itself "Webhook for archive having new binary package" [Undecided,New] https://launchpad.net/bugs/1638333
[13:43:39] <cjwatson> well, that would only help if LP had a webhook receiver too
[13:43:53] <cjwatson> or some external thing to do the logic
[13:44:12] <cjwatson> basically, it'll be a non-trivial project and it isn't clear exactly what would be the best route