platformclasspath_classes folder not writable since 6.0.0-pre.20220517.1

[deepy]

Description of the bug:

Starting in 6.0.0-pre.20220517.1 the platformclasspath_classes is no longer writable which prevents DumpPlatformClassPath.class from being deleted.
This is causing our tests to fail when trying to cleanup or work with the directory.

rm: cannot remove '/home/deepy/.cache/bazel/_bazel_deepy/8edfe17b4be90513bcf6c070303d6f06/execroot/__main__/bazel-out/k8-fastbuild/bin/external/bazel_tools/tools/jdk/platformclasspath_classes/DumpPlatformClassPath.class': Permission denied

$ ls -la .
dr-xr-xr-x 2 deepy deepy  4096 Jun  3 10:20 .
drwxr-xr-x 3 deepy deepy  4096 Jun  3 10:20 ..
-r-xr-xr-x 1 deepy deepy 10139 Jun  3 10:20 DumpPlatformClassPath.class

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

Build examples/java-tutorial with --output_base

bazel --output_base=mytest build //:ProjectRunner

Then rm -rf mytest

rm: cannot remove './mytest/execroot/__main__/bazel-out/k8-fastbuild/bin/external/bazel_tools/tools/jdk/platformclasspath_classes/DumpPlatformClassPath.class': Permission denied

Which operating system are you running Bazel on?

Linux

What is the output of bazel info release?

6.0.0-pre.20220526.1

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 ?

No response

Have you found anything relevant by searching the web?

No response

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

No response

[fmeum]

This changed with ae523f8. Before that commit, the output of the action that compiles DumpPlatformClassPath was a non-writable class file, now it is a non-writable directory containing a class file. The same would apply to any other directory output produced by a Bazel rule. While probably working as intended from the perspective of Bazel (rule outputs that are used as inputs should not be writable), it is inconvenient that a simple rm -rf isn't able to remove the tree.

@deepy Can you use chmod -R u=rwx mytest before doing the rm -rf mytest?

[deepy]

The problem there is that when we add changing permissions into the mix we can't rely on automatic cleanup by other tools any longer and with multiple operating systems in the mix this becomes even less fun to deal with.
And if we delete it too eagerly it's going to impact test execution times 😞

[fmeum]

Have you tried bazel clean --expunge --output_base=mytest? This is Bazel-specific, but should work on all OSes.

[deepy]

We've worked around this, thank you for the explanation, all the information, and the workaround suggestions!

[hashar]

I encounter the same issue with Bazel 5.3.1. To start a fresh build we do find bazel-out -delete and that chokes on the lack of writable permission (see also our issue tracker)