[BUG] [HEADS UP] Cython build failure with Python 3.14.0a1

[befeleme]

Describe the bug

I try to build Cython 3.0.11 with Python 3.14.0a1 in Fedora Linux and get the following errors:

  Error compiling Cython file:
  ------------------------------------------------------------
  ...
      return op, pos

  def p_binop_expr(s, ops, p_sub_expr):
      n1 = p_sub_expr(s)
      while s.sy in ops:
          op, pos = p_binop_operator(s)
                                     ^
  ------------------------------------------------------------

  Cython/Compiler/Parsing.py:99:35: Compiler crash in AnalyseExpressionsTransform

  ModuleNode.body = StatListNode(Parsing.py:6:0)
  StatListNode.stats[25] = StatListNode(Parsing.py:96:0)
  StatListNode.stats[0] = CFuncDefNode(Parsing.py:96:0,
      args = [...]/3,
      modifiers = [...]/0,
      outer_attrs = [...]/2,
      visibility = 'private')
  File 'Nodes.py', line 397, in analyse_expressions: StatListNode(Parsing.py:97:4,
      is_terminator = True)
  File 'Nodes.py', line 7354, in analyse_expressions: WhileStatNode(Parsing.py:98:4)
  File 'Nodes.py', line 397, in analyse_expressions: StatListNode(Parsing.py:99:8)
  File 'Nodes.py', line 6056, in analyse_expressions: SingleAssignmentNode(Parsing.py:99:34)
  File 'Nodes.py', line 6189, in analyse_types: SingleAssignmentNode(Parsing.py:99:34)
  File 'ExprNodes.py', line 6139, in analyse_types: SimpleCallNode(Parsing.py:99:34,
      analysed = True,
      result_is_used = True,
      use_managed_ref = True)
  File 'ExprNodes.py', line 6257, in analyse_c_function_call: SimpleCallNode(Parsing.py:99:34,
      analysed = True,
      result_is_used = True,
      use_managed_ref = True)
  File 'ExprNodes.py', line 2076, in coerce_to: NameNode(Parsing.py:99:35,
      cf_state = [...]/1,
      is_name = True,
      name = 's',
      result_is_used = True,
      use_managed_ref = True)
  File 'ExprNodes.py', line 983, in coerce_to: NameNode(Parsing.py:99:35,
      cf_state = [...]/1,
      is_name = True,
      name = 's',
      result_is_used = True,
      use_managed_ref = True)

  Compiler crash traceback from this point on:
    File "/builddir/build/BUILD/Cython-3.0.11-build/cython-3.0.11/Cython/Compiler/ExprNodes.py", line 983, in coerce_to
      if src_type.is_cv_qualified:
         ^^^^^^^^^^^^^^^^^^^^^^^^
  AttributeError: 'NoneType' object has no attribute 'is_cv_qualified'
  Compiling /builddir/build/BUILD/Cython-3.0.11-build/cython-3.0.11/Cython/Compiler/Parsing.py because it changed.
  [1/1] Cythonizing /builddir/build/BUILD/Cython-3.0.11-build/cython-3.0.11/Cython/Compiler/Parsing.py
  Traceback (most recent call last):
    File "/usr/lib/python3.14/site-packages/pip/_vendor/pyproject_hooks/_in_process/_in_process.py", line 353, in <module>
      main()
      ~~~~^^
    File "/usr/lib/python3.14/site-packages/pip/_vendor/pyproject_hooks/_in_process/_in_process.py", line 335, in main
      json_out['return_val'] = hook(**hook_input['kwargs'])
                               ~~~~^^^^^^^^^^^^^^^^^^^^^^^^
    File "/usr/lib/python3.14/site-packages/pip/_vendor/pyproject_hooks/_in_process/_in_process.py", line 251, in build_wheel
      return _build_backend().build_wheel(wheel_directory, config_settings,
             ~~~~~~~~~~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
                                          metadata_directory)
                                          ^^^^^^^^^^^^^^^^^^^
    File "/usr/lib/python3.14/site-packages/setuptools/build_meta.py", line 410, in build_wheel
      return self._build_with_temp_dir(
             ~~~~~~~~~~~~~~~~~~~~~~~~~^
          ['bdist_wheel'],
          ^^^^^^^^^^^^^^^^
      ...<3 lines>...
          self._arbitrary_args(config_settings),
          ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
      )
      ^
    File "/usr/lib/python3.14/site-packages/setuptools/build_meta.py", line 395, in _build_with_temp_dir
      self.run_setup()
      ~~~~~~~~~~~~~~^^
    File "/usr/lib/python3.14/site-packages/setuptools/build_meta.py", line 487, in run_setup
      super().run_setup(setup_script=setup_script)
      ~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^
    File "/usr/lib/python3.14/site-packages/setuptools/build_meta.py", line 311, in run_setup
      exec(code, locals())
      ~~~~^^^^^^^^^^^^^^^^
    File "<string>", line 319, in <module>
    File "<string>", line 245, in run_build
    File "/usr/lib/python3.14/site-packages/setuptools/__init__.py", line 104, in setup
      return distutils.core.setup(**attrs)
             ~~~~~~~~~~~~~~~~~~~~^^^^^^^^^
    File "/usr/lib/python3.14/site-packages/setuptools/_distutils/core.py", line 185, in setup
      return run_commands(dist)
    File "/usr/lib/python3.14/site-packages/setuptools/_distutils/core.py", line 201, in run_commands
      dist.run_commands()
      ~~~~~~~~~~~~~~~~~^^
    File "/usr/lib/python3.14/site-packages/setuptools/_distutils/dist.py", line 969, in run_commands
      self.run_command(cmd)
      ~~~~~~~~~~~~~~~~^^^^^
    File "/usr/lib/python3.14/site-packages/setuptools/dist.py", line 967, in run_command
      super().run_command(command)
      ~~~~~~~~~~~~~~~~~~~^^^^^^^^^
    File "/usr/lib/python3.14/site-packages/setuptools/_distutils/dist.py", line 988, in run_command
      cmd_obj.run()
      ~~~~~~~~~~~^^
    File "/usr/lib/python3.14/site-packages/wheel/bdist_wheel.py", line 368, in run
      self.run_command("build")
      ~~~~~~~~~~~~~~~~^^^^^^^^^
    File "/usr/lib/python3.14/site-packages/setuptools/_distutils/cmd.py", line 318, in run_command
      self.distribution.run_command(command)
      ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^^^^^^^^^
    File "/usr/lib/python3.14/site-packages/setuptools/dist.py", line 967, in run_command
      super().run_command(command)
      ~~~~~~~~~~~~~~~~~~~^^^^^^^^^
    File "/usr/lib/python3.14/site-packages/setuptools/_distutils/dist.py", line 988, in run_command
      cmd_obj.run()
      ~~~~~~~~~~~^^
    File "/usr/lib/python3.14/site-packages/setuptools/_distutils/command/build.py", line 131, in run
      self.run_command(cmd_name)
      ~~~~~~~~~~~~~~~~^^^^^^^^^^
    File "/usr/lib/python3.14/site-packages/setuptools/_distutils/cmd.py", line 318, in run_command
      self.distribution.run_command(command)
      ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^^^^^^^^^
    File "/usr/lib/python3.14/site-packages/setuptools/dist.py", line 967, in run_command
      super().run_command(command)
      ~~~~~~~~~~~~~~~~~~~^^^^^^^^^
    File "/usr/lib/python3.14/site-packages/setuptools/_distutils/dist.py", line 988, in run_command
      cmd_obj.run()
      ~~~~~~~~~~~^^
    File "/usr/lib/python3.14/site-packages/setuptools/_distutils/command/build_ext.py", line 345, in run
      self.build_extensions()
      ~~~~~~~~~~~~~~~~~~~~~^^
    File "/usr/lib/python3.14/site-packages/setuptools/_distutils/command/build_ext.py", line 467, in build_extensions
      self._build_extensions_serial()
      ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^^
    File "/usr/lib/python3.14/site-packages/setuptools/_distutils/command/build_ext.py", line 493, in _build_extensions_serial
      self.build_extension(ext)
      ~~~~~~~~~~~~~~~~~~~~^^^^^
    File "/builddir/build/BUILD/Cython-3.0.11-build/cython-3.0.11/Cython/Distutils/build_ext.py", line 130, in build_extension
      new_ext = cythonize(
                ~~~~~~~~~^
          ext,force=self.force, quiet=self.verbose == 0, **options
          ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
      )[0]
      ^
    File "/builddir/build/BUILD/Cython-3.0.11-build/cython-3.0.11/Cython/Build/Dependencies.py", line 1154, in cythonize
      cythonize_one(*args)
      ~~~~~~~~~~~~~^^^^^^^
    File "/builddir/build/BUILD/Cython-3.0.11-build/cython-3.0.11/Cython/Build/Dependencies.py", line 1321, in cythonize_one
      raise CompileError(None, pyx_file)
  Cython.Compiler.Errors.CompileError: /builddir/build/BUILD/Cython-3.0.11-build/cython-3.0.11/Cython/Compiler/Parsing.py
  Building wheel for Cython (pyproject.toml): finished with status 'error'

Code to reproduce the behaviour:

No response

Expected behaviour

No response

OS

Fedora Linux

Python version

Python 3.14.0a1

Cython version

3.0.11

Additional context

Build happened in our test build system. Happy to test fixes.

[hroncok]

I can reproduce this at cython master branch @ a2b9f55 (also with Python 3.14.0a1).

[hroncok]

Actually, my error is a bit different, but I build it a bit differently:

[1/1] Cythonizing .../cython/Cython/Compiler/Parsing.py
warning: Cython/Compiler/Parsing.py:100:0: noexcept clause is ignored for function returning Python object
warning: Cython/Compiler/Parsing.py:197:0: noexcept clause is ignored for function returning Python object

Error compiling Cython file:
------------------------------------------------------------
...


@cython.ccall
def make_slice_node(pos, start, stop = None, step = None):
    if not start:
        start = ExprNodes.NoneNode(pos)
                                  ^
------------------------------------------------------------

Cython/Compiler/Parsing.py:750:34: Compiler crash in AnalyseExpressionsTransform

ModuleNode.body = StatListNode(Parsing.py:8:0)
StatListNode.stats[65] = StatListNode(Parsing.py:747:0)
StatListNode.stats[0] = CompilerDirectivesNode(Parsing.py:747:0)
CompilerDirectivesNode.body = StatListNode(Parsing.py:747:0)
StatListNode.stats[0] = CFuncDefNode(Parsing.py:747:0,
    args = [...]/4,
    modifiers = [...]/0,
    outer_attrs = [...]/2,
    overridable = True,
    visibility = 'private')
File 'Nodes.py', line 400, in analyse_expressions: StatListNode(Parsing.py:749:4,
    is_terminator = True)
File 'Nodes.py', line 344, in analyse_expressions: CompilerDirectivesNode(Parsing.py:749:4,
    is_terminator = True)
File 'Nodes.py', line 400, in analyse_expressions: StatListNode(Parsing.py:749:4,
    is_terminator = True)
File 'Nodes.py', line 7250, in analyse_expressions: IfStatNode(Parsing.py:749:4)
File 'Nodes.py', line 7297, in analyse_expressions: IfClauseNode(Parsing.py:749:7)
File 'Nodes.py', line 400, in analyse_expressions: StatListNode(Parsing.py:750:34)
File 'Nodes.py', line 6133, in analyse_expressions: SingleAssignmentNode(Parsing.py:750:34)
File 'Nodes.py', line 6266, in analyse_types: SingleAssignmentNode(Parsing.py:750:34)
File 'ExprNodes.py', line 6124, in analyse_types: SimpleCallNode(Parsing.py:750:34,
    analysed = True,
    result_is_used = True,
    use_managed_ref = True)
File 'ExprNodes.py', line 8643, in analyse_types: TupleNode(Parsing.py:750:34,
    is_sequence_constructor = 1,
    result_is_used = True,
    use_managed_ref = True)

Compiler crash traceback from this point on:
  File ".../cython/Cython/Compiler/ExprNodes.py", line 8643, in analyse_types
    if len(self.args) == 0:
       ~~~^^^^^^^^^^^
TypeError: object of type 'NoneType' has no len()
Traceback (most recent call last):
  File ".../cython/setup.py", line 356, in <module>
    run_build()
    ~~~~~~~~~^^
  File ".../cython/setup.py", line 278, in run_build
    setup(
    ~~~~~^
        name='Cython',
        ^^^^^^^^^^^^^^
    ...<71 lines>...
        **setup_args
        ^^^^^^^^^^^^
    )
    ^
  File ".../cython/venv/lib64/python3.14/site-packages/setuptools/__init__.py", line 117, in setup
    return distutils.core.setup(**attrs)
           ~~~~~~~~~~~~~~~~~~~~^^^^^^^^^
  File ".../cython/venv/lib64/python3.14/site-packages/setuptools/_distutils/core.py", line 183, in setup
    return run_commands(dist)
  File ".../cython/venv/lib64/python3.14/site-packages/setuptools/_distutils/core.py", line 199, in run_commands
    dist.run_commands()
    ~~~~~~~~~~~~~~~~~^^
  File ".../cython/venv/lib64/python3.14/site-packages/setuptools/_distutils/dist.py", line 954, in run_commands
    self.run_command(cmd)
    ~~~~~~~~~~~~~~~~^^^^^
  File ".../cython/venv/lib64/python3.14/site-packages/setuptools/dist.py", line 991, in run_command
    super().run_command(command)
    ~~~~~~~~~~~~~~~~~~~^^^^^^^^^
  File ".../cython/venv/lib64/python3.14/site-packages/setuptools/_distutils/dist.py", line 973, in run_command
    cmd_obj.run()
    ~~~~~~~~~~~^^
  File ".../cython/venv/lib64/python3.14/site-packages/setuptools/_distutils/command/build.py", line 135, in run
    self.run_command(cmd_name)
    ~~~~~~~~~~~~~~~~^^^^^^^^^^
  File ".../cython/venv/lib64/python3.14/site-packages/setuptools/_distutils/cmd.py", line 316, in run_command
    self.distribution.run_command(command)
    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^^^^^^^^^
  File ".../cython/venv/lib64/python3.14/site-packages/setuptools/dist.py", line 991, in run_command
    super().run_command(command)
    ~~~~~~~~~~~~~~~~~~~^^^^^^^^^
  File ".../cython/venv/lib64/python3.14/site-packages/setuptools/_distutils/dist.py", line 973, in run_command
    cmd_obj.run()
    ~~~~~~~~~~~^^
  File ".../cython/venv/lib64/python3.14/site-packages/setuptools/command/build_ext.py", line 98, in run
    _build_ext.run(self)
    ~~~~~~~~~~~~~~^^^^^^
  File ".../cython/venv/lib64/python3.14/site-packages/setuptools/_distutils/command/build_ext.py", line 359, in run
    self.build_extensions()
    ~~~~~~~~~~~~~~~~~~~~~^^
  File ".../cython/venv/lib64/python3.14/site-packages/setuptools/_distutils/command/build_ext.py", line 476, in build_extensions
    self._build_extensions_serial()
    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^^
  File ".../cython/venv/lib64/python3.14/site-packages/setuptools/_distutils/command/build_ext.py", line 502, in _build_extensions_serial
    self.build_extension(ext)
    ~~~~~~~~~~~~~~~~~~~~^^^^^
  File ".../cython/venv/lib64/python3.14/site-packages/setuptools/command/build_ext.py", line 263, in build_extension
    _build_ext.build_extension(self, ext)
    ~~~~~~~~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^
  File ".../cython/Cython/Distutils/build_ext.py", line 129, in build_extension
    new_ext = cythonize(
              ~~~~~~~~~^
        ext,force=self.force, quiet=self.verbose == 0, **options
        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    )[0]
    ^
  File ".../cython/Cython/Build/Dependencies.py", line 1109, in cythonize
    cythonize_one(*args)
    ~~~~~~~~~~~~~^^^^^^^
  File ".../cython/Cython/Build/Dependencies.py", line 1256, in cythonize_one
    raise CompileError(None, pyx_file)
Cython.Compiler.Errors.CompileError: .../cython/Cython/Compiler/Parsing.py

[scoder]

The crashes apparently happen while running Cython as pure Python code that translates a Python module in Cython itself. That suggests a bug in CPython rather than Cython. Recent work in CPython is strongly geared towards performance improvements, touching almost all parts of the implementation. While there is a certain chance that we're doing something special in Cython's Python code, I wouldn't be surprised to see further user code breakage in CPython, especially in an early alpha release. I still remember Victor's "break the world" move in Py3.13a1. This seems small in comparison.

[hroncok]

I still remember Victor's "break the world" move in Py3.13a1.

See https://discuss.python.org/t/remove-again-private-apis-which-now-have-new-public-replacement/68081/1 about that for 3.14 (he's asking what to do so it's a chance to influence the course of action).

---

The "crash" seem to be this:

  Compiler crash traceback from this point on:
    File "/builddir/build/BUILD/Cython-3.0.11-build/cython-3.0.11/Cython/Compiler/ExprNodes.py", line 983, in coerce_to
      if src_type.is_cv_qualified:
         ^^^^^^^^^^^^^^^^^^^^^^^^
  AttributeError: 'NoneType' object has no attribute 'is_cv_qualified'

Compiler crash traceback from this point on:
  File ".../cython/Cython/Compiler/ExprNodes.py", line 8643, in analyse_types
    if len(self.args) == 0:
       ~~~^^^^^^^^^^^
TypeError: object of type 'NoneType' has no len()

This does not sound like "interpreter crush" to me, but honestly this is a bit too magical for me :)

[tacaswell]

I also see this with CPython main, I'm working on bisecting it.

[tacaswell]

@ git bisect log
# bad: [2e950e341930ea79549137d4d3771d5edb940e65] Add tests for time.strftime() with invalid format string (GH-125696)
# good: [8204014280fcb07c9321305a729716326e625c6e] [3.13] Add tests for time.strftime() with invalid format string (GH-125696) (GH-125702)
git bisect start 'main' '3.13'
# good: [2268289a47c6e3c9a220b53697f9480ec390466f] Python 3.13.0b1
git bisect good 2268289a47c6e3c9a220b53697f9480ec390466f
# good: [d52726ccd456833ea9f09cabb4b8aef09755e472] Document ``mimetypes.MimeTypes.add_type()`` (#122301)
git bisect good d52726ccd456833ea9f09cabb4b8aef09755e472
# good: [aba42c0b547e6395c9c268cf98a298d0494cb9df] gh-123969: refactor _PyErr_RaiseSyntaxError and _PyErr_EmitSyntaxWarning out of compiler (#123972)
git bisect good aba42c0b547e6395c9c268cf98a298d0494cb9df
# bad: [1d4e3e0585c1051ec182666668137fbb0fc1a4d2] gh-111178: Fix locale_free() signature (#124896)
git bisect bad 1d4e3e0585c1051ec182666668137fbb0fc1a4d2
# bad: [909c6f718913e713c990d69e6d8a74c05f81e2c2] gh-123884 Tee of tee was not producing n independent iterators (gh-124490)
git bisect bad 909c6f718913e713c990d69e6d8a74c05f81e2c2
# good: [c87b0e4a462f98c418f750c6c95d4d8715c38332] GH-124284: Add stats for refcount operations on immortal objects (GH-124288)
git bisect good c87b0e4a462f98c418f750c6c95d4d8715c38332
# bad: [4a5e4aade420c594c5b3fe0589e9e6b444bd6ee5] gh-59317: Improve parsing optional positional arguments in argparse (GH-124303)
git bisect bad 4a5e4aade420c594c5b3fe0589e9e6b444bd6ee5
# good: [38a887dc3ec52c4a7222279bf4b3ca2431b86de9] gh-119004: fix a crash in equality testing between `OrderedDict` (#121329)
git bisect good 38a887dc3ec52c4a7222279bf4b3ca2431b86de9
# bad: [9d344fafc4385cb2e17425b77b54660ca83c61ac] gh-124127: Make Py_REFCNT() opaque in limited C API 3.14 (#124128)
git bisect bad 9d344fafc4385cb2e17425b77b54660ca83c61ac
# bad: [d87482bc4ee9458d6ba16140e7bc008637dbbb16] gh-119333: Add C api to have contextvar enter/exit callbacks (#119335)
git bisect bad d87482bc4ee9458d6ba16140e7bc008637dbbb16
# bad: [be76e3f26e0b907f711497d006b8b83bff04c036] gh-100980: ctypes: Test, document, and fix finalizing _fields_ (GH-124292)
git bisect bad be76e3f26e0b907f711497d006b8b83bff04c036
# good: [e256a7590a0149feadfef161ed000991376dc0e8] Lint and format Tools/build/check-warnings.py (#124382)
git bisect good e256a7590a0149feadfef161ed000991376dc0e8
# first bad commit: [be76e3f26e0b907f711497d006b8b83bff04c036] gh-100980: ctypes: Test, document, and fix finalizing _fields_ (GH-124292)

via python/cpython#124292

(git bisect run ... is super usful!)

[scoder]

python/cpython#124292

That's a change in ctypes, though. We don't use that anywhere. I don't see how that change could be related.

[tacaswell]

hmm, something went wrong with my bisect script as the log claims e256a7590a0149feadfef161ed000991376dc0e8 worked, but trying again does not...

[tacaswell]

A second attempt (I think starting from 3.13 as the "good" version confused git with the branch)

@ git bisect log
git bisect start
# status: waiting for both good and bad commits
# good: [5a1205b641df133932ed4c65b9a4ff5724e89963] gh-111499: Fix PYTHONMALLOCSTATS at Python exit (#120021)
git bisect good 5a1205b641df133932ed4c65b9a4ff5724e89963
# status: waiting for bad commit, 1 good commit known
# bad: [2e950e341930ea79549137d4d3771d5edb940e65] Add tests for time.strftime() with invalid format string (GH-125696)
git bisect bad 2e950e341930ea79549137d4d3771d5edb940e65
# bad: [7b8328b6b33939dfff4606d286b10069a09223dd] GH-121723: Skip test_config_queue_handler_multiprocessing_context in emulated JIT CI (#122969)
git bisect bad 7b8328b6b33939dfff4606d286b10069a09223dd
# good: [59be79ae60073f7b6bdf6ce921560c279937e4ab] gh-108297: Update crashers README for test_crashers removal (#121475)
git bisect good 59be79ae60073f7b6bdf6ce921560c279937e4ab
# good: [bb108580dec5d8655ccdfb6c8737b5f64e3366d0] gh-122087: Add tests for ismethoddescriptor() and isroutine() with partial objects (GH-122219)
git bisect good bb108580dec5d8655ccdfb6c8737b5f64e3366d0
# good: [06eb9701a182b4720dfa8766cb41cc5a3728a8b9] Doc: Grammar fix in ``library/ssl.rst``, 'Verifying certificates' (#122646)
git bisect good 06eb9701a182b4720dfa8766cb41cc5a3728a8b9
# bad: [57d7c3e78fb635a0c6ccce38ec3e2f4284d5fac7] gh-122247: Move instruction instrumentation sanity check after tracing check (#122251)
git bisect bad 57d7c3e78fb635a0c6ccce38ec3e2f4284d5fac7
# bad: [4b66b6b7d6e65f9eb2d61435b9b37ffeb7bb00fb] gh-120104: IDLE: Fix padding in config and search dialogs (#120107)
git bisect bad 4b66b6b7d6e65f9eb2d61435b9b37ffeb7bb00fb
# bad: [44659d392751f0161a0f958fec39ad013da45427] GH-118943: Handle races when moving jit_stencils.h (GH-120690)
git bisect bad 44659d392751f0161a0f958fec39ad013da45427
# good: [f5c39b3e9cc88d1eaa9229d610b0221305a83ad9] gh-122661: Remove GNU make-specific directive from Doc/Makefile (#122662)
git bisect good f5c39b3e9cc88d1eaa9229d610b0221305a83ad9
# good: [5207adf228547273b0e8d0253c23c69b95d7fe11] build(deps-dev): bump mypy from 1.10.1 to 1.11.1 in /Tools (#122550)
git bisect good 5207adf228547273b0e8d0253c23c69b95d7fe11
# good: [1bb955a2fe0237721c141fdfe520fd3ba46db11e] gh-122459: Optimize pickling by name objects without __module__ (GH-122460)
git bisect good 1bb955a2fe0237721c141fdfe520fd3ba46db11e
# bad: [5bd72912a1a85be96092de302608a4298741c6cd] GH-122616: Simplify LOAD_ATTR_WITH_HINT and STORE_ATTR_WITH_HINT (GH-122620)
git bisect bad 5bd72912a1a85be96092de302608a4298741c6cd
# first bad commit: [5bd72912a1a85be96092de302608a4298741c6cd] GH-122616: Simplify LOAD_ATTR_WITH_HINT and STORE_ATTR_WITH_HINT (GH-122620)

However, this produces a slightly different error:

      [1/1] Cythonizing /home/tcaswell/source/p/cython/cython/Cython/Compiler/Parsing.py
      warning: Cython/Compiler/Parsing.py:100:0: noexcept clause is ignored for function returning Python object
      warning: Cython/Compiler/Parsing.py:197:0: noexcept clause is ignored for function returning Python object

      Error compiling Cython file:
      ------------------------------------------------------------
      ...
              if ctx.api:
                  s.error("'api' not allowed with this statement", fatal=False)
              elif s.sy == 'def':
                  # def statements aren't allowed in pxd files, except
                  # as part of a cdef class
                  if ('pxd' in ctx.level) and (ctx.level != 'c_class_pxd'):
                            ^
      ------------------------------------------------------------

      Cython/Compiler/Parsing.py:2598:22: Compiler crash in AnalyseExpressionsTransform

      ModuleNode.body = StatListNode(Parsing.py:8:0)
      StatListNode.stats[138] = StatListNode(Parsing.py:2530:0)
      StatListNode.stats[0] = CompilerDirectivesNode(Parsing.py:2530:0)
      CompilerDirectivesNode.body = StatListNode(Parsing.py:2530:0)
      StatListNode.stats[0] = CFuncDefNode(Parsing.py:2530:0,
          args = [...]/3,
          modifiers = [...]/0,
          outer_attrs = [...]/2,
          visibility = 'private')
      File 'Nodes.py', line 400, in analyse_expressions: StatListNode(Parsing.py:2532:4)
      File 'Nodes.py', line 344, in analyse_expressions: CompilerDirectivesNode(Parsing.py:2532:4)
      File 'Nodes.py', line 400, in analyse_expressions: StatListNode(Parsing.py:2532:4)
      File 'Nodes.py', line 7252, in analyse_expressions: IfStatNode(Parsing.py:2579:4)
      File 'Nodes.py', line 400, in analyse_expressions: StatListNode(Parsing.py:2593:8)
      File 'Nodes.py', line 7250, in analyse_expressions: IfStatNode(Parsing.py:2593:8)
      File 'Nodes.py', line 7297, in analyse_expressions: IfClauseNode(Parsing.py:2595:13,
          is_terminator = True)
      File 'Nodes.py', line 400, in analyse_expressions: StatListNode(Parsing.py:2598:12,
          is_terminator = True)
      File 'Nodes.py', line 7250, in analyse_expressions: IfStatNode(Parsing.py:2598:12)
      File 'Nodes.py', line 7296, in analyse_expressions: IfClauseNode(Parsing.py:2598:15)
      File 'ExprNodes.py', line 644, in analyse_temp_boolean_expression: BoolBinopNode(Parsing.py:2598:36,
          is_temp = True,
          operator = 'and',
          result_is_used = True,
          use_managed_ref = True)
      File 'ExprNodes.py', line 12937, in analyse_types: BoolBinopNode(Parsing.py:2598:36,
          is_temp = True,
          operator = 'and',
          result_is_used = True,
          use_managed_ref = True)
      File 'ExprNodes.py', line 13718, in analyse_types: PrimaryCmpNode(Parsing.py:2598:22,
          operator = 'in',
          result_is_used = True,
          use_managed_ref = True)
      File 'ExprNodes.py', line 13476, in is_ptr_contains: PrimaryCmpNode(Parsing.py:2598:22,
          operator = 'in',
          result_is_used = True,
          use_managed_ref = True)

      Compiler crash traceback from this point on:
        File "/home/tcaswell/source/p/cython/cython/Cython/Compiler/ExprNodes.py", line 13476, in is_ptr_contains
          return (container_type.is_ptr or container_type.is_array) \
                  ^^^^^^^^^^^^^^^^^^^^^
      AttributeError: 'NoneType' object has no attribute 'is_ptr'

so I also worry that it has been broken/fixed a couple of times which is also making the bisect hard.

[da-woods]

If I had to take a wild guess I'd think it might be something going wrong with __hash__ or __eq__ for the contents of PyrexTypes.py. We were certainly caught be a change in the behaviour if you get an exception while evaluating __eq__ in 3.13 (which I think was concluded to be "our fault") so it's possible that something similar might be happening again.

That it a complete guess though, just based on the idea that we've seen something similar before and it does look like types aren't been found correctly.

[scoder]

Yeah, the symptoms hint at something like __hash__. Also that the error appears unstable – the hash variation across Python runs may well induce that. I'll try if setting PYTHONHASHSEED makes the bisect more stable.

EDIT: The concrete error varies in similar ways, so it's not simply that.

[scoder]

I've reported the issue in the original CPython PR for now.

[da-woods]

I've created the issue python/cpython#125868. Definitely a Python bug not a Cython bug - I get some very weird output from pdb.