Building Bazel from source on Power9 fails with "Could not find a JDK for host execution environment"

[Flamefire]

Description of the problem / feature request:

I'd like to build bazel for Power9 (ppc64le) but it fails with a JDK related issue

Bugs: what's the simplest, easiest way to reproduce this bug? Please provide a minimal example if possible.

Use a PPC system with openJDK 8 (javac 1.8.0-internal, or javac 1.8.0_222), download the source (*-dist.zip) and do ./compile.sh

What operating system are you running Bazel on?

RHEL 7.6

Have you found anything relevant by searching the web?

#10049
#7943
#8313
#6557
Pretty much this issue: https://stackoverflow.com/questions/56584783/bazel-buid-app-to-buildconfigurable-attribute-actual-doesnt-match-this-co

Any other information, logs, or outputs that you want to share?

🍃  Building Bazel from scratch......
🍃  Building Bazel with Bazel.
.WARNING: --batch mode is deprecated. Please instead explicitly shut down your Bazel server using the command "bazel shutdown".
DEBUG: /tmp/bazel_gPZKDF3H/out/external/bazel_toolchains/rules/rbe_repo/version_check.bzl:59:9: 
Current running Bazel is not a release version and one was not defined explicitly in rbe_autoconfig target. Falling back to '0.27.1'
DEBUG: /tmp/bazel_gPZKDF3H/out/external/bazel_toolchains/rules/rbe_repo/checked_in.bzl:103:9: rbe_ubuntu1804_java11 not using checked in configs as detect_java_home was set to True 
DEBUG: /tmp/bazel_gPZKDF3H/out/external/bazel_toolchains/rules/rbe_repo/version_check.bzl:59:9: 
Current running Bazel is not a release version and one was not defined explicitly in rbe_autoconfig target. Falling back to '0.27.1'
DEBUG: /tmp/bazel_gPZKDF3H/out/external/bazel_toolchains/rules/rbe_repo/checked_in.bzl:103:9: rbe_ubuntu1604_java8 not using checked in configs as detect_java_home was set to True 
DEBUG: /tmp/bazel_gPZKDF3H/out/external/build_bazel_rules_nodejs/internal/common/check_bazel_version.bzl:49:5: 
Current Bazel is not a release version, cannot check for compatibility.
DEBUG: /tmp/bazel_gPZKDF3H/out/external/build_bazel_rules_nodejs/internal/common/check_bazel_version.bzl:51:5: Make sure that you are running at least Bazel 0.17.1.
ERROR: /tmp/bazel_gPZKDF3H/out/external/bazel_tools/tools/jdk/BUILD:492:14: Configurable attribute "actual" doesn't match this configuration: Could not find a JDK for host execution environment, please explicitly provide one using `--host_javabase.`
INFO: Call stack for the definition of repository 'remote_java_tools_linux' which is a http_archive (rule definition at /tmp/bazel_gPZKDF3H/out/external/bazel_tools/tools/build_defs/repo/http.bzl:262:16):
 - /DEFAULT.WORKSPACE.SUFFIX:240:1
ERROR: Analysis of target '//src:bazel_nojdk' failed; build aborted: 

/tmp/bazel_gPZKDF3H/out/external/bazel_tools/tools/jdk/BUILD:492:14: Configurable attribute "actual" doesn't match this configuration: Could not find a JDK for host execution environment, please explicitly provide one using `--host_javabase.`
INFO: Elapsed time: 7,462s
INFO: 0 processes.
FAILED: Build did NOT complete successfully (113 packages loaded, 699 targets \
configured)
    currently loading: @bazel_tools//src/tools/launcher ... (2 packages)
    Fetching @local_jdk; Restarting.

ERROR: Could not build Bazel

[Flamefire]

Apparently using EXTRA_BAZEL_ARGS='--host_javabase=@local_jdk//:jdk' ./compile.sh does work, but I don't fully understand the implications. If that is sane, couldn't this be used as a fallback/default?

[wdirons]

Apparently using EXTRA_BAZEL_ARGS='--host_javabase=@local_jdk//:jdk' ./compile.sh does work, but I don't fully understand the implications. If that is sane, couldn't this be used as a fallback/default?

Yes, that is how I build bazel on Power (https://github.com/tensorflow/tensorflow/blob/master/tensorflow/tools/ci_build/install/install_bazel_from_source.sh)

That just means it it using the JDK on the host machine and not the version embedded in Bazel.

For the latest Bazel versions I have been using openjdk 11.

[Flamefire]

And what does it mean for the so installed Bazel? Will it continue using the system JDK? Will it bundle the system JDK?

However I can confirm that this at least works with openJDK 8 to build TensorFlow 2.0.0 on our Power system.

And finally:

If that is sane, couldn't this be used as a fallback/default? (In Bazel itself)

[wdirons]

Bazel built this way will use the system JDK.

[philwo]

IIUC a solution / workaround was given in the discussion here. Please reopen if this is still an issue.