add more platform options in the PPA

Hi beuno, can you give your two cents on this one, please? Thanks!

PPAs only build binaries on i386, amd64 and lpia, so the user interface is correct.

The repo indexes contain entries for other arches because that PPA contains some arch-all sources (documentation, from what I see).

Perhaps Celso can comment on whether we should be generating indexes for the other arches?

Yes, architecture independent binaries are published to all ubuntu known architectures in the PPA context as well.

It allows users of other architectures to install arch:all packages via `apt` as they could do by downloading the binaries `gdebi` or `dpkg`.

I'm unsure about how to promote their existence, though. At moment, source that produce architecture independent binaries are not clearly represented in the UI, that's something we should consider in the overview page redesign as well.

Martin, do you have any idea to make it clearer ?

Maybe putting an option for each single platform? (If a package is platform indipendent, it would be appear as every single platform?)

I'm sorry Fabio, I don't understand your suggestion.

PPA supports i386,amd64 and lpia. A uploader, who constructed the source package, decided in which architecture he wants to build a it (all, any, specific ones) and Launchpad does exactly what it asked to and shows the binaries in the PPA page. All debian/ubuntu tools (and users, for that matter) know that architecture-independent binaries can be installed in any platform, including the ones that are not directly supported in PPAs.

That understood, what kind of UI change you are suggestion us to do ?

bug #156904 suggests we simply stop publishing arch-all only indexes for unsupported architectures in PPAs.

I'm not sure, but maybe that would set the message right in this area. PPA only builds and publish i386, amd64 and lpia.

I think LP should be able to compile at least: i386, amd64, lpia and arm

@Fabio what we can compile is limited by virtualisation support for different targets, and we have other bugs about that. As per bug 683140 we plan to stop publishing the arch-all only files for non-PPA architectures, which will solve the confusion; I'm marking this as a dup of that bug.