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Unhandled BytesWarning when test.support.strace_helper.strace_python fails #127747
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@andreas-schwab Could you provide some more details about the error? For example: which platform are you using, how did you start the tests (from the message above I gather you are running the cpython unit tests), how did you install or compile cpython, is python itself running as expected?
This is the actual test failure:
test test_subprocess crashed -- Traceback (most recent call last): File "/home/abuild/rpmbuild/BUILD/Python-3.14.0a2/Lib/test/libregrtest/single.py", line 181, in _runtest_env_changed_exc _load_run_test(result, runtests) ~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^ File "/home/abuild/rpmbuild/BUILD/Python-3.14.0a2/Lib/test/libregrtest/single.py", line 128, in _load_run_test test_mod = importlib.import_module(module_name) File "/home/abuild/rpmbuild/BUILD/Python-3.14.0a2/Lib/importlib/__init__.py", line 88, in import_module return _bootstrap._gcd_import(name[level:], package, level) ~~~~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ File "<frozen importlib._bootstrap>", line 1386, in _gcd_import File "<frozen importlib._bootstrap>", line 1359, in _find_and_load File "<frozen importlib._bootstrap>", line 1330, in _find_and_load_unlocked File "<frozen importlib._bootstrap>", line 935, in _load_unlocked File "<frozen importlib._bootstrap_external>", line 756, in exec_module File "<frozen importlib._bootstrap>", line 488, in _call_with_frames_removed File "/home/abuild/rpmbuild/BUILD/Python-3.14.0a2/Lib/test/test_subprocess.py", line 1843, in <module> class POSIXProcessTestCase(BaseTestCase): ...<1628 lines>... self.assertNotRegex(non_vfork_result.event_bytes, br"(?i)vfork") File "/home/abuild/rpmbuild/BUILD/Python-3.14.0a2/Lib/test/test_subprocess.py", line 3420, in POSIXProcessTestCase @strace_helper.requires_strace() ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^^ File "/home/abuild/rpmbuild/BUILD/Python-3.14.0a2/Lib/test/support/strace_helper.py", line 166, in requires_strace return unittest.skipUnless(_can_strace(), "Requires working strace") ~~~~~~~~~~~^^ File "/home/abuild/rpmbuild/BUILD/Python-3.14.0a2/Lib/test/support/strace_helper.py", line 153, in _can_strace res = strace_python("import sys; sys.exit(0)", [], check=False) File "/home/abuild/rpmbuild/BUILD/Python-3.14.0a2/Lib/test/support/strace_helper.py", line 105, in strace_python return _make_error("Expected strace events and exit code line", stripped[-50:]) File "/home/abuild/rpmbuild/BUILD/Python-3.14.0a2/Lib/test/support/strace_helper.py", line 85, in _make_error event_bytes=f"error({reason},details={details}) = -1".encode('utf-8'), ^^^^^^^^^ BytesWarning: str() on a bytes instance- changed the title
[-]AssertionError: unhandled warning {message : BytesWarning('str() on a bytes instance'), category : 'BytesWarning', filename : '/home/abuild/rpmbuild/BUILD/Python-3.14.0a2/Lib/test/support/strace_helper.py', lineno : 85, line : None}[/-][+]Uhandled warning in `test_subprocess`[/+]on Dec 8, 2024 - changed the title
[-]Uhandled warning in `test_subprocess`[/-][+]Unhandled `BytesWarning('str() on a bytes instance')` in `test_subprocess`[/+]on Dec 8, 2024 Please, tell us how Python was configured and installed and how the tests were executed.
https://build.opensuse.org/package/live_build_log/openSUSE:Factory:RISCV/python314/standard/riscv64
./configure --host=riscv64-suse-linux --build=riscv64-suse-linux --program-prefix= --disable-dependency-tracking --prefix=/usr --exec-prefix=/usr --bindir=/usr/bin --sbindir=/usr/sbin --sysconfdir=/etc --datadir=/usr/share --includedir=/usr/include --libdir=/usr/lib64 --libexecdir=/usr/libexec --localstatedir=/var --sharedstatedir=/var/lib --mandir=/usr/share/man --infodir=/usr/share/info --with-platlibdir=lib64 --docdir=/usr/share/doc/packages/python --enable-ipv6 --enable-shared --with-ensurepip=no --with-system-ffi --with-system-expat --with-lto --with-ssl-default-suites=openssl --enable-optimizations --with-system-libmpdec --enable-loadable-sqlite-extensions
make
make testOk, my best guess is that the
stracehelper is not found, so something is raised. However, when we raise that error, we usedetails, which is likely a bytes instance and not a string one. Why? becausedetailsis probably obtained from stderr ofsubprocess.run(...)used to check the presence ofstrace, and we likely forgot to decode the output.I'll check this tomorrow and provide a patch if needed.
The error seems to be in
AutoFileTests.test_syscalls_readaccording to your logs. Note that thetest_vfork_used_when_expectedis also affected and it's actually the decorator that fails.cc @cmaloney as the one who added this decorator.
Reacted by Cody MaloneyWalking through the warning log + code looks like the strace binary exists but gave unexpected output. That leads to a call to the
_make_errorhelper (https://github.com/python/cpython/blob/main/Lib/test/support/strace_helper.py#L103-L109) where details is abytesrather than anOSErrororstr. I'd been using f-strings to format the output, and there is an implicit conversion from bytes -> str there... Not sure if there's a common / preferred way to fix, will experiment a bit.No, there is no strace installed.
Reacted by Cody Maloney- added a commit that references this issue
on Dec 10, 2024 - changed the title
[-]Unhandled `BytesWarning('str() on a bytes instance')` in `test_subprocess`[/-][+]Unhandled `BytesWarning('str() on a bytes instance')` when `test.support.strace_helper.strace_python` fails[/+]on Dec 10, 2024 - changed the title
[-]Unhandled `BytesWarning('str() on a bytes instance')` when `test.support.strace_helper.strace_python` fails[/-][+]Unhandled `BytesWarning when `test.support.strace_helper.strace_python` fails[/+]on Dec 10, 2024 - changed the title
[-]Unhandled `BytesWarning when `test.support.strace_helper.strace_python` fails[/-][+]Unhandled `BytesWarning` when `test.support.strace_helper.strace_python` fails[/+]on Dec 10, 2024
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