Update protobuf to 3.7.1

[davido]

No description provided.

[davido]

//CC @drigz @laurentlb @meteorcloudy.

Note, that 3.7.1 wasn't tagged yet on the protobuf side. I used the code from this commit on 3.7.x branch: protocolbuffers/protobuf@4b9a5df. This was the backport of my fix from master: [1].

[1] protocolbuffers/protobuf#5811

[davido]

It seems that Protobuf is using bazel_skylib now. Tests are failing:

ERROR: /home/davido/.cache/bazel/_bazel_davido/4596c3304267e4c44bca87d41e038f29/sandbox/linux-sandbox/1669/execroot/io_bazel/_tmp/69b4d07d7f58456ce79df1b29fbdc766/workspace/test_modify_execution_info_various_types/BUILD:24:1: every rule of type proto_library implicitly depends upon the target '@com_google_protobuf//:protoc', but this target could not be found because of: error loading package '@com_google_protobuf//': in /home/davido/.cache/bazel/_bazel_davido/4596c3304267e4c44bca87d41e038f29/sandbox/linux-sandbox/1669/execroot/io_bazel/_tmp/69b4d07d7f58456ce79df1b29fbdc766/root/cccd58d5baf92601474e7dca6142d199/external/com_google_protobuf/protobuf.bzl: Unable to load package for '@bazel_skylib//lib:versions.bzl': The repository '@bazel_skylib' could not be resolved
ERROR: Analysis of target '//test_modify_execution_info_various_types:proto' failed; build aborted: error loading package '@com_google_protobuf//': in /home/davido/.cache/bazel/_bazel_davido/4596c3304267e4c44bca87d41e038f29/sandbox/linux-sandbox/1669/execroot/io_bazel/_tmp/69b4d07d7f58456ce79df1b29fbdc766/root/cccd58d5baf92601474e7dca6142d199/external/com_google_protobuf/protobuf.bzl: Unable to load package for '@bazel_skylib//lib:versions.bzl': The repository '@bazel_skylib' could not be resolved

In previous version, 3.6.1 Protobuf was using native.bazel_version version check. This was changed in this commit: protocolbuffers/protobuf@b2a1908. I don't think we want to bring bazel_skylib dependency to Bazel itself to bootstrap protobuf. So that the way forward could be to revert that commit in Bazel Protobuf fork and remove dependency on bazel_skylib, and check for the minimum required Bazel version in the same way, as it was done in older Protobuf versions:

  expected = apple_common.dotted_version("0.5.4")
  current = apple_common.dotted_version(native.bazel_version)
  if current.compare_to(expected) < 0:
    fail("Bazel must be newer than 0.5.4")

[aiuto]

Note to reviewers: I added people who had done this update before. Could one of you please volunteer to follow it by de-assigning the others, or fully assigning it to yourselves. We don't need 3 people on it.

[laszlocsomor]

David, what's to motivation for this PR, what is 3.6.1 (and 3.7.0) missing?

[davido]

David, what's to motivation for this PR, what is 3.6.1 (and 3.7.0) missing?

Upgrade to the recent protobuf release (3.7.0) is needed to make Bazel build tool chain forward compatible (incompatible options).

Upgrade to 3.7.x branch is needed, because 3.7.0 is missing this fix: [1].

[1] protocolbuffers/protobuf#5811

[laszlocsomor]

Thank you.

Please send out PR 1 alone first, and PRs 2..4 after PR 1 is merged.

Rationale: separately, they are easier to review and roll back.

[davido]

@laszlocsomor

Please send out PR 1 alone first, and PRs 2..4 after PR 1 is merged.

OK, will do once I figured out how to fix test breakages. There are two complications compared to previous protobuf version upgrades:

• Dependency on bazel_skylib
• Dependency on zlib

[laszlocsomor]

@davido : Thanks. Let me know if you need help.

[davido]

@laszlocsomor Most of the test jobs are passing now. But some (flaky) are still failing. Do you have any clou, what is going on here? Thanks!

[laszlocsomor]

I'll take a look.

[laszlocsomor]

@davido: I'll create a separate PR of your PR 1 (026afdb). It must be merged directly to https://bazel.googlesource.com/bazel/+/master, and I don't know if you have permission to merge there. Does that sound good?

[davido]

@laszlocsomor

Does that sound good?

Thank you. Your help is very much appreciated!

[iirina]

@laszlocsomor was this PR merged? Could you please close the PR when/if it's closed? Thanks!

[laszlocsomor]

@iirina : It wasn't, we're debating whether it's required. Will close afterwards.

See #7775

[jin]

@laszlocsomor can this be closed if #7775 is closed?

[laszlocsomor]

Yes.