Open
Description
Bug report
The culprit is that for some reason calling perf from the WSL raises a PermissionError, rather than FileNotFoundError or CalledProcessError when perf is not available.
Example output:
$ which perf # not present
$ ./python -m test test_perf_profiler -v
== CPython 3.15.0a0 (heads/main:3704171415c, May 31 2025, 12:20:03) [Clang 20.1.6 (++20250528122018+47addd4540b4-1~exp1~20250528002033.124)]
== Linux-6.6.87.1-microsoft-standard-WSL2-x86_64-with-glibc2.39 little-endian
== Python build: debug
== cwd: /home/emma/cpython/build/test_python_worker_7822æ
== CPU count: 32
== encodings: locale=UTF-8 FS=utf-8
== resources: all test resources are disabled, use -u option to unskip tests
Using random seed: 1838771651
0:00:00 load avg: 0.65 Run 1 test sequentially in a single process
0:00:00 load avg: 0.65 [1/1] test_perf_profiler
test test_perf_profiler crashed -- Traceback (most recent call last):
File "/home/emma/cpython/Lib/test/libregrtest/single.py", line 210, in _runtest_env_changed_exc
_load_run_test(result, runtests)
~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^
File "/home/emma/cpython/Lib/test/libregrtest/single.py", line 155, in _load_run_test
test_mod = importlib.import_module(module_name)
File "/home/emma/cpython/Lib/importlib/__init__.py", line 88, in import_module
return _bootstrap._gcd_import(name[level:], package, level)
~~~~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "<frozen importlib._bootstrap>", line 1398, in _gcd_import
File "<frozen importlib._bootstrap>", line 1371, in _find_and_load
File "<frozen importlib._bootstrap>", line 1342, in _find_and_load_unlocked
File "<frozen importlib._bootstrap>", line 938, in _load_unlocked
File "<frozen importlib._bootstrap_external>", line 762, in exec_module
File "<frozen importlib._bootstrap>", line 491, in _call_with_frames_removed
File "/home/emma/cpython/Lib/test/test_perf_profiler.py", line 522, in <module>
_is_perf_version_at_least(6, 6), "perf command may not work due to a perf bug"
~~~~~~~~~~~~~~~~~~~~~~~~~^^^^^^
File "/home/emma/cpython/Lib/test/test_perf_profiler.py", line 510, in _is_perf_version_at_least
output = subprocess.check_output(["perf", "--version"], text=True)
File "/home/emma/cpython/Lib/subprocess.py", line 472, in check_output
return run(*popenargs, stdout=PIPE, timeout=timeout, check=True,
~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
**kwargs).stdout
^^^^^^^^^
File "/home/emma/cpython/Lib/subprocess.py", line 554, in run
with Popen(*popenargs, **kwargs) as process:
~~~~~^^^^^^^^^^^^^^^^^^^^^^
File "/home/emma/cpython/Lib/subprocess.py", line 1038, in __init__
self._execute_child(args, executable, preexec_fn, close_fds,
~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
pass_fds, cwd, env,
^^^^^^^^^^^^^^^^^^^
...<5 lines>...
gid, gids, uid, umask,
^^^^^^^^^^^^^^^^^^^^^^
start_new_session, process_group)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/home/emma/cpython/Lib/subprocess.py", line 1970, in _execute_child
raise child_exception_type(errno_num, err_msg, err_filename)
PermissionError: [Errno 13] Permission denied: 'perf'
0:00:00 load avg: 0.65 [1/1/1] test_perf_profiler failed (uncaught exception)
== Tests result: FAILURE ==
1 test failed:
test_perf_profiler
Total duration: 270 ms
Total tests: run=0
Total test files: run=1/1 failed=1
Result: FAILURE