Python3.12 test error: SyntaxError: unmatched ')'

[Petr Vaněk]

Test suit fails with Python3.12 with following error message:

======================================================= ERRORS ========================================================
__________________________________ ERROR collecting tests/hypothesis_vector_test.py ___________________________________
/usr/lib/python3.12/site-packages/_pytest/python.py:617: in _importtestmodule
    mod = import_path(self.path, mode=importmode, root=self.config.rootpath)
/usr/lib/python3.12/site-packages/_pytest/pathlib.py:564: in import_path
    importlib.import_module(module_name)
/usr/lib/python3.12/importlib/__init__.py:90: in import_module
    return _bootstrap._gcd_import(name[level:], package, level)
<frozen importlib._bootstrap>:1293: in _gcd_import
    ???
<frozen importlib._bootstrap>:1266: in _find_and_load
    ???
<frozen importlib._bootstrap>:1237: in _find_and_load_unlocked
    ???
<frozen importlib._bootstrap>:841: in _load_unlocked
    ???
/usr/lib/python3.12/site-packages/_pytest/assertion/rewrite.py:178: in exec_module
    exec(co, module.__dict__)
tests/hypothesis_vector_test.py:48: in <module>
    PVectorAndLists = st.lists(st.builds(RefCountTracker)).map(
/usr/lib/python3.12/site-packages/hypothesis/strategies/_internal/strategies.py:347: in map
    if is_identity_function(pack):
/usr/lib/python3.12/site-packages/hypothesis/internal/reflection.py:638: in is_identity_function
    return bool(re.fullmatch(r"lambda (\w+): \1", get_pretty_function_description(f)))
/usr/lib/python3.12/site-packages/hypothesis/internal/reflection.py:432: in get_pretty_function_description
    return extract_lambda_source(f)
/usr/lib/python3.12/site-packages/hypothesis/internal/reflection.py:312: in extract_lambda_source
    source = inspect.getsource(f)
/usr/lib/python3.12/inspect.py:1274: in getsource
    lines, lnum = getsourcelines(object)
/usr/lib/python3.12/inspect.py:1266: in getsourcelines
    return getblock(lines[lnum:]), lnum + 1
/usr/lib/python3.12/inspect.py:1241: in getblock
    for _token in tokens:
/usr/lib/python3.12/tokenize.py:451: in _tokenize
    for token in _generate_tokens_from_c_tokenizer(source, extra_tokens=True):
/usr/lib/python3.12/tokenize.py:542: in _generate_tokens_from_c_tokenizer
    for info in c_tokenizer.TokenizerIter(source, extra_tokens=extra_tokens):
E     File "<string>", line 1
E       lambda l: (l, pvector(l)))
E                                ^
E   SyntaxError: unmatched ')'
================================================== warnings summary ===================================================
../../../../../../../usr/lib/python3.12/site-packages/_pytest/assertion/rewrite.py:691
  /usr/lib/python3.12/site-packages/_pytest/assertion/rewrite.py:691: DeprecationWarning: Attribute s is deprecated and will be removed in Python 3.14; use value instead
    doc = item.value.s

-- Docs: https://docs.pytest.org/en/stable/how-to/capture-warnings.html
=============================================== short test summary info ===============================================
ERROR tests/hypothesis_vector_test.py
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! Interrupted: 1 error during collection !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
============================================= 1 warning, 1 error in 2.68s =============================================

However, all tests pass when I apply this change:

--- a/tests/hypothesis_vector_test.py
+++ b/tests/hypothesis_vector_test.py
@@ -45,8 +45,7 @@ def test_setup(gc_when_done):


 # Pairs of a list and corresponding pvector:
-PVectorAndLists = st.lists(st.builds(RefCountTracker)).map(
-    lambda l: (l, pvector(l)))
+PVectorAndLists = st.lists(st.builds(RefCountTracker)).map(lambda l: (l, pvector(l)) )


 def verify_inputs_unmodified(original):

[Michał Górny]

This turned out to be actually a bug in CPython.