Building for ARM systems

[Aleix Pol]

Dear Flatpak'ers,
As some of you already know, I've been poking around trying to find
some kind of system where we can build the KDE runtime and
applications for ARM.
Now I can add that it's been without much luck. I'm sending this
e-mail with my experience to put the problem in perspective so we can
see if there's something we can do about it.

To clarify a bit, my goal initially was to get to run our applications
on the Plasma Phone through Flatpak [1]. It's a Nexus 5, running an
armhf ubuntu-based beast.

To compile it I thought it would work just to get a cheap-ish hosting
service and use it for to build the binaries. I tried:
- scaleway: there it wouldn't even start doing anything, presumably
because it was missing neon?
- "mything beasts" rpi hosting: somebody suggested it on #flatpak, the
distro they have is too old and we can't add the ppa there for
dependencies reasons. Didn't push it further.
- rpi3 at home: using the SD was unbearably slow (we're talking ~1h to
install the Freedesktop SDK) and I didn't have much time to spend on
it. There could be some optimal set up, but I'm not convinced.

Anybody has a good idea of how to proceed?
Would it make sense to invest some time into seeing if it's possible
to cross-compile? I've seen some approach WRT using qemu too.

Thanks!
Aleix

[1] https://twitter.com/AleixPol/status/834051053645594624