build_tar attempts to use python2 when upgrading to Bazel 6.0.0

[nicknezis]

Description of the bug:

After upgrading to Bazel 6.0.0. I am getting the following failure when building the Apache Heron project.

failed: (Exit 127): build_tar failed: error executing command (from target //scripts/packages:heron-core-lib-downloader) bazel-out/darwin-py2-opt-exec-2B5CBBC6/bin/external/rules_pkg/build_tar

When testing with Bazel 5.1.0 the issue does not occur. Is there something relating to this toolchain definition that is failing? https://github.com/bazelbuild/bazel/blob/6.0.0/tools/python/toolchain.bzl

My build machine is a darwin (MacOS), and I have brew installed Python 3.9 and 3.10. I do not have any form of Python 2 installed.

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

git clone git@github.com:apache/incubator-heron.git
echo 6.0.0 > .bazelversion
bazel build scripts/packages:heron-bin

Which operating system are you running Bazel on?

macOS Ventura 13.1

What is the output of bazel info release?

release 6.0.0

If bazel info release returns development version or (@non-git), tell us how you built Bazel.

No response

What's the output of git remote get-url origin; git rev-parse master; git rev-parse HEAD ?

https://github.com/apache/incubator-heron
8aa05b8449ad5a3c2cd27f12c82f75d192c99da9
e49a043e5f046132a88e9242c30df96f718976bb

Have you found anything relevant by searching the web?

No response

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

No response

[nicknezis]

Sample build log output: https://app.travis-ci.com/github/apache/incubator-heron/builds/259485593#L435

[sgowroji]

Seems that project as support upto 4.2.2 https://github.com/apache/incubator-heron#heron-requirements

[nicknezis]

@sgowroji sorry, I should of linked to the feature branch in which I am attempting to upgrade to Bazel 6.0.0. I am one of the maintainers of this Apache project.

apache/incubator-heron#3863

[nicknezis]

Actually I think it's ok to keep this closed. I think with the removal of pkg_tar from 6.0.0, this uncovered an implicit dependency on skylib that rules_python has. It's documented here. bazelbuild/rules_python#932