Error in building snap package on launchpad

Question

I'm trying to create a snap build on launchpad for my application.

I'm able to build the application fine on launchpad normally, however the snap build is failing with the following error:

W:GPG error: http://ppa.launchpad.net/snappy-dev/tools/ubuntu yakkety InRelease: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY F1831DDAFC42E99D, E:The repository 'http://ppa.launchpad.net/snappy-dev/tools/ubuntu yakkety InRelease' is not signed.

I'm not sure if this is a problem with the snapcraft.yaml that I have writted and added to launchpad : http://bazaar.launchpad.net/~bablu-boy/nutty/trunk/view/head:/snapcraft.yaml

The snap build page on launchpad is here.The build log of the latest snap build has the above error.

Appreciate any help in resolving this issue. Thanks in advance !

Answer 1

This is a bit complicated, and I'm not sure I can resolve it for you on the spot. You've found a bug.

Normally, Launchpad doesn't bother to ship out public keys for the archives it asks its builders to build against, since they're all in our datacentre on trusted networks. This is maybe not ideal, but we configure sbuild to allow unauthenticated archives and so it usually only results in a cosmetic warning.

However, in this case, snapcraft is set up to borrow the build system's apt configuration in order to fetch the packages you've listed in stage-packages, and it doesn't seem to know to also borrow the configuration that allows unauthenticated archives. Thus, things fail.

I think the best fix is probably to change Launchpad to ship the necessary public keys to the builders, at least for snap builds. While it isn't strictly needed in most cases, the strange warning confuses people sometimes even when it doesn't cause a hard failure, and it would be a nice piece of hardening. Please could you file a bug about this?

Separately, I see that you're running into a bzr bug when you tried to build against the primary archive, but at least that one is known and we should have it fixed fairly soon.

Update: This is finally all fixed now. You'll need to change your snapcraft.yaml a bit for series later than xenial because they don't have valac-0.30-vapi (for yakkety, use valac-0.32-vapi, and for zesty, use valac-0.34-vapi; other changes may be needed), but that's all the kind of thing that you should be able to sort out in your build system.