Forthcoming Bazel 6 release breaks Drake's python coverage support

[rpoyner-tri]

What happened?

I let the Ubuntu update tools bump bazel to 6.0, then tried to do a bazel test --config kcov build. It fails, with stack traces from the bazel-generated python wrapper stubs when trying to collect python coverage data.

Version

cb7d2b7

What operating system are you using?

Ubuntu 20.04

What installation option are you using?

compiled from source code using Bazel

Relevant log output

rico@puget-161804-10:~/checkout/drake$ bazel --version
bazel 6.0.0
rico@puget-161804-10:~/checkout/drake$ bazel test --config kcov //bindings/pydrake/common/... 
Starting local Bazel server and connecting to it...
INFO: Analyzed 27 targets (229 packages loaded, 15822 targets configured).
INFO: Found 27 test targets...
FAIL: //bindings/pydrake/common:py/eigen_pybind_test (see /home/rico/.cache/bazel/_bazel_rico/7f8997f28c9253517a55d673c67a6c74/execroot/drake/bazel-out/k8-opt/testlogs/bindings/pydrake/common/py/eigen_pybind_test/test.log)
INFO: From Testing //bindings/pydrake/common:py/eigen_pybind_test:
==================== Test output for //bindings/pydrake/common:py/eigen_pybind_test:
Traceback (most recent call last):
  File "/home/rico/.cache/bazel/_bazel_rico/7f8997f28c9253517a55d673c67a6c74/execroot/drake/bazel-out/k8-opt/bin/bindings/pydrake/common/py/eigen_pybind_test.runfiles/drake/bindings/pydrake/common/py/eigen_pybind_test", line 541, in <module>
    Main()
  File "/home/rico/.cache/bazel/_bazel_rico/7f8997f28c9253517a55d673c67a6c74/execroot/drake/bazel-out/k8-opt/bin/bindings/pydrake/common/py/eigen_pybind_test.runfiles/drake/bindings/pydrake/common/py/eigen_pybind_test", line 527, in Main
    ExecuteFile(
  File "/home/rico/.cache/bazel/_bazel_rico/7f8997f28c9253517a55d673c67a6c74/execroot/drake/bazel-out/k8-opt/bin/bindings/pydrake/common/py/eigen_pybind_test.runfiles/drake/bindings/pydrake/common/py/eigen_pybind_test", line 343, in ExecuteFile
    ret_code = _RunForCoverage(python_program, main_filename, args, env,
  File "/home/rico/.cache/bazel/_bazel_rico/7f8997f28c9253517a55d673c67a6c74/execroot/drake/bazel-out/k8-opt/bin/bindings/pydrake/common/py/eigen_pybind_test.runfiles/drake/bindings/pydrake/common/py/eigen_pybind_test", line 380, in _RunForCoverage
    with open(rcfile_name, "w") as rcfile:
FileNotFoundError: [Errno 2] No such file or directory: '/home/rico/.cache/bazel/_bazel_rico/7f8997f28c9253517a55d673c67a6c74/execroot/drake/bazel-out/k8-opt/testlogs/bindings/pydrake/common/py/eigen_pybind_test/test.outputs/kcov/.coveragerc'
================================================================================
...

[rpoyner-tri]

Patch in progress.

[rpoyner-tri]

See #18616