[Mesa-dev] CI for Android builds

[Rob Herring]

I've made some improvements to my mesa Android CI job[1]. Previously,
it just built using master twice a day and only emailed me. Now anyone
(with commit rights) can push to mesa branches master or android/* and
it will trigger a build emailing the last commit's author/committer on
failure.

It's slower than I'd like for a couple of reasons. It takes ~15
minutes just to clone an AOSP tree and does that from scratch each
time. The AOSP trees have daily bandwidth limits on them and will
start to refuse a given IP address if you clone too many times in one
day. So I've limited the build frequency to every 2 hours (just a
guess whether this will be low enough). That also means the wrong
person could be emailed for the failure if subsequent commits happen
in that window (but master is supposed to be the last resort, push to
android/* first!). I could point to a Linaro mirror instead, but want
to see how this works first. It should also be possible to craft a
trimmed down manifest with just the repos we need to build.

Also, if master or any previous build was already failing, then you
won't get an email. So you have to fix master first. Maybe that's a
feature. :) I think I need to split master and android/* branch builds
to separate jobs to handle this case. The alternative is every push to
master will spam people after the Android build breaks.

Rob

[1] https://ci.linaro.org/view/All/job/robher-aosp/