Checked in config needed for Bazel 4.1.0

[davido]

We cannot build Gerrit on RBE with new and shiny Bazel 4.1.0 release yet (released earlier today):

  $ bazel build --config=remote --remote_instance_name=<RBE-Project>  :gerrit
INFO: Invocation ID: 8efa7885-f3ed-4425-ac7c-861071de4b7d
INFO: Options provided by the client:
  Inherited 'common' options: --isatty=1 --terminal_columns=159
INFO: Reading rc options for 'build' from /home/davido/projects/gerrit/.bazelrc:
  'build' options: --workspace_status_command=python3 ./tools/workspace_status.py --repository_cache=~/.gerritcodereview/bazel-cache/repository --action_env=PATH --disk_cache=~/.gerritcodereview/bazel-cache/cas --java_toolchain=//tools:error_prone_warnings_toolchain_java11 --incompatible_strict_action_env --announce_rc
INFO: Reading rc options for 'build' from /home/davido/.bazelrc:
  'build' options: --experimental_generate_json_trace_profile --experimental_profile_cpu_usage
INFO: Found applicable config definition build:remote in file /home/davido/projects/gerrit/tools/remote-bazelrc: --jobs=200 --disk_cache= --host_javabase=@rbe_jdk11//java:jdk --javabase=@rbe_jdk11//java:jdk --crosstool_top=@rbe_jdk11//cc:toolchain --extra_toolchains=@rbe_jdk11//config:cc-toolchain --extra_execution_platforms=@rbe_jdk11//config:platform --host_platform=@rbe_jdk11//config:platform --platforms=@rbe_jdk11//config:platform --action_env=BAZEL_DO_NOT_DETECT_CPP_TOOLCHAIN=1 --define=EXECUTOR=remote --remote_cache=remotebuildexecution.googleapis.com --remote_executor=remotebuildexecution.googleapis.com --remote_timeout=3600 --google_default_credentials
DEBUG: /home/davido/.cache/bazel/_bazel_davido/27a001f4182820ef315d8d2d4f1edafe/external/bazel_toolchains/rules/rbe_repo/version_check.bzl:68:14: 
Current running Bazel is ahead of bazel-toolchains repo. Please update your pin to bazel-toolchains repo in your WORKSPACE file.
DEBUG: /home/davido/.cache/bazel/_bazel_davido/27a001f4182820ef315d8d2d4f1edafe/external/bazel_toolchains/rules/rbe_repo/checked_in.bzl:125:14: rbe_jdk11 not using checked in configs; Bazel version 4.1.0 was picked/selected but no checked in config was found in map {"0.20.0": ["8.0.0"], "0.21.0": ["8.0.0"], "0.22.0": ["8.0.0", "9.0.0"], "0.23.0": ["8.0.0", "9.0.0"], "0.23.1": ["8.0.0", "9.0.0"], "0.23.2": ["9.0.0"], "0.24.0": ["9.0.0"], "0.24.1": ["9.0.0"], "0.25.0": ["9.0.0"], "0.25.1": ["9.0.0"], "0.25.2": ["9.0.0"], "0.26.0": ["9.0.0"], "0.26.1": ["9.0.0"], "0.27.0": ["9.0.0"], "0.27.1": ["9.0.0"], "0.28.0": ["9.0.0"], "0.28.1": ["9.0.0"], "0.29.0": ["9.0.0"], "0.29.1": ["9.0.0", "10.0.0"], "1.0.0": ["9.0.0", "10.0.0"], "1.0.1": ["10.0.0"], "1.1.0": ["10.0.0"], "1.2.0": ["10.0.0"], "1.2.1": ["10.0.0"], "2.0.0": ["10.0.0"], "2.1.0": ["10.0.0"], "2.1.1": ["10.0.0", "11.0.0"], "2.2.0": ["11.0.0"], "3.0.0": ["11.0.0"], "3.1.0": ["11.0.0"], "3.2.0": ["11.0.0"], "3.3.0": ["11.0.0"], "3.3.1": ["11.0.0"], "3.4.1": ["11.0.0"], "3.5.0": ["11.0.0"], "3.5.1": ["11.0.0"], "3.6.0": ["11.0.0"], "3.7.0": ["11.0.0"], "3.7.1": ["11.0.0"], "3.7.2": ["11.0.0"], "4.0.0": ["11.0.0"]}
INFO: Repository rbe_jdk11 instantiated at:
  /home/davido/projects/gerrit/WORKSPACE:48:15: in <toplevel>
  /home/davido/.cache/bazel/_bazel_davido/27a001f4182820ef315d8d2d4f1edafe/external/bazel_toolchains/rules/rbe_repo.bzl:1217:20: in rbe_autoconfig
Repository rule _rbe_autoconfig defined at:
  /home/davido/.cache/bazel/_bazel_davido/27a001f4182820ef315d8d2d4f1edafe/external/bazel_toolchains/rules/rbe_repo.bzl:654:34: in <toplevel>
DEBUG: /home/davido/.cache/bazel/_bazel_davido/27a001f4182820ef315d8d2d4f1edafe/external/bazel_toolchains/rules/rbe_repo.bzl:492:10: Bazel 4.1.0 is used in rbe_jdk11.
ERROR: An error occurred during the fetch of repository 'rbe_jdk11':

@philwo

Can we automate it? Or add a TODO to the Bazel release process, to avoid the delay?

[davido]

I figured, there is a workaround:

diff --git a/WORKSPACE b/WORKSPACE
index 0caf8c3d20..f7db0158c0 100644
--- a/WORKSPACE
+++ b/WORKSPACE
@@ -47,6 +47,7 @@ load("@bazel_toolchains//rules:rbe_repo.bzl", "rbe_autoconfig")
 # Creates a default toolchain config for RBE.
 rbe_autoconfig(
     name = "rbe_jdk11",
+    bazel_version = "4.0.0",
     java_home = "/usr/lib/jvm/11.29.3-ca-jdk11.0.2/reduced",
     use_checked_in_confs = "Force",
 )

It works and the I see this log output:

DEBUG: /home/davido/.cache/bazel/_bazel_davido/5c01f4f713b675540b8b424c5c647f63/external/bazel_toolchains/rules/rbe_repo.bzl:492:10: Bazel 4.0.0 is used in rbe_jdk11.

[philwo]

@davido Sorry, bazel-toolchains 4.x and the rbe-ubuntu1604 container are no longer maintained. Your workaround looks fine to me! While you're on 4.x, I would recommend to bump your version to bazel-toolchains 4.1.0 to avoid hitting another incompatibility that we found.

Context:

• RBE pre- and postsubmit broken due to broken bazel-toolchains version check bazel#13502
• Release 4.1 - May 2021 bazel#13099 (comment)

We're also currently researching and figuring out how to make it easy to switch to bazel-toolchains 5.x, but I'm about to go on vacation for two weeks, so I'll follow up on that when I'm back.