Flogger needs Android 29

[comius]

After fix in bazel:
bazelbuild/bazel#11737

Downstream project "Flogger" needs Android 29.

(Downstream build: https://buildkite.com/bazel/bazel-at-head-plus-downstream/builds/1573#4bcf1123-f2bb-4a59-b232-95290d726609)
Culprit: https://buildkite.com/bazel/culprit-finder/builds/421)

cc: @juliexxia, @katre

[katre]

Flogger has requires Android 29 since the last set of updates. Attempting to roll back bazelbuild/bazel@20b95dd would hide the problem again, but not actually solve it.

We should update the CI to include Android 29 as well as 24 and 28.

[philwo]

I'll add Android 29 support to our CI.

[katre]

Looks like flogger uses bazel-common, which has required Android 29 since google/bazel-common@4c4c70b, last October.

[katre]

Flogger itself doesn't use Android directly, so arguably they should push back on bazel-common over this, but I'm not sure what we can do about that.

[cpovirk]

Speaking as someone who has not quite enough context on any piece of this :) (but who randomly stumbled across this thread -- to be clear, not because I noticed a Bazel-Flogger problem):

• My understanding is that Android does recommend installing and targeting the newest SDK, so it seems nice for Bazel CI to support it. (That said, I think some people do build against a different SDK internally... though maybe usually against a newer, experimental one, rather than an older one?) In particular, it seems like Dagger (and bazel-common itself) could want to use Bazel CI instead of our current Travis setups. (And the Dagger team was the one to update bazel-common to Android 29, though I didn't see specific discussion of the motivation in internal CL 276329131 or CL 276783784.)
• Nevertheless, it does seem unfortunate for Flogger specifically to require an Android SDK at all. bazel-common should probably make Android support (continue to be) optional. Probably it would have been that way from the beginning if bazelbuild/bazel@20b95dd had been in place then.

[c-parsons]

Any updates here? Flogger continues to fail in buildkite.
https://buildkite.com/bazel/bazel-at-head-plus-downstream/builds/1603#5deed360-d6da-42e5-b43d-103912441e54

@philwo any guidance on how we add Android 29 to CI? :)

[philwo]

There was a blocker for updating our Android build-tools on the CI machines, but my colleagues told me that it has been resolved with a fix to Bazel now. I've just pushed new VM images to the testing CI, when all looks good they'll go to production CI later.

However, they have build-tools 29.0.3 installed, while the linked bazel-common commit above references 29.0.2. 😬 How hard is it to update that to 29.0.3?

[katre]

We'd need to update bazel-common, then update flogger (and other projects) to use the new bazel-common. It's doable but several steps. Can we have multiple Android SDKs, or does that make the image too large?

[philwo]

I'll install that version, too, so you're unblocked. We can migrate whenever we have time, no problem.

[philwo]

I just realized this isn't (only) about the build-tools, but the whole Android 29 platform was missing. I'll add it to the VMs.

[philwo]

All done and happy to report that it's green now: https://buildkite.com/bazel/bazel-at-head-plus-downstream/builds/1603#aae5670f-6be4-4cdc-b581-df28e38441d2 🎉