Crash report
What happened?
It's possible to abort a JIT build by running the code below:
def f1(): class AsyncIter: def __init__(self): self.limit = 0 self.count = 0 def __aiter__(self): return self async def __anext__(self): if self.count >= self.limit: ... self.count += 1j class AsyncCtx: async def async_for_driver(): try: for _ in range(5000): try: async for _ in AsyncIter(): ... except TypeError: ... except Exception: ... c = async_for_driver() while True: try: c.send(None) except StopIteration: break for i in range(30): f1()
Backtrace:
python: Python/intrinsics.c:145: PyObject *stopiteration_error(PyThreadState *, PyObject *): Assertion `PyExceptionInstance_Check(exc)' failed.
Program received signal SIGABRT, Aborted.
#0 __pthread_kill_implementation (threadid=<optimized out>, signo=6, no_tid=0) at ./nptl/pthread_kill.c:44
#1 __pthread_kill_internal (threadid=<optimized out>, signo=6) at ./nptl/pthread_kill.c:89
#2 __GI___pthread_kill (threadid=<optimized out>, signo=signo@entry=6) at ./nptl/pthread_kill.c:100
#3 0x00007ffff7c45e2e in __GI_raise (sig=sig@entry=6) at ../sysdeps/posix/raise.c:26
#4 0x00007ffff7c28888 in __GI_abort () at ./stdlib/abort.c:77
#5 0x00007ffff7c287f0 in __assert_fail_base (fmt=<optimized out>, assertion=<optimized out>, file=<optimized out>, line=<optimized out>, function=<optimized out>) at ./assert/assert.c:118
#6 0x00007ffff7c3c19f in __assert_fail (assertion=<optimized out>, file=<optimized out>, line=<optimized out>, function=<optimized out>) at ./assert/assert.c:127
#7 0x0000555555fe5142 in stopiteration_error (tstate=0x555556e6afb0 <_PyRuntime+359376>, exc=0x555556beeaa0 <_Py_TrueStruct>) at Python/intrinsics.c:145
#8 0x0000555555e76230 in _PyEval_EvalFrameDefault (tstate=<optimized out>, frame=<optimized out>, throwflag=<optimized out>) at Python/generated_cases.c.h:2589
#9 0x0000555555b4168b in _PyEval_EvalFrame (tstate=0x555556e6afb0 <_PyRuntime+359376>, frame=0x7d0ffd203528, throwflag=0) at ./Include/internal/pycore_ceval.h:119
#10 gen_send_ex2 (gen=0x7d0ffd2034e0, arg=0x555556c0b4a0 <_Py_NoneStruct>, presult=0x7bfff5bad660, exc=0) at Objects/genobject.c:239
#11 0x0000555555b420f5 in gen_send (op=0x7d0ffd2034e0, arg=0x555556c0b4a0 <_Py_NoneStruct>) at Objects/genobject.c:365
#12 0x0000555555ea7bc7 in _PyEval_EvalFrameDefault (tstate=<optimized out>, frame=<optimized out>, throwflag=<optimized out>) at Python/generated_cases.c.h:3661
#13 0x0000555555e6db18 in _PyEval_EvalFrame (tstate=0x555556e6afb0 <_PyRuntime+359376>, frame=0x7e8ff6fe5310, throwflag=0) at ./Include/internal/pycore_ceval.h:119
#14 _PyEval_Vector (tstate=<optimized out>, func=<optimized out>, locals=<optimized out>, args=<optimized out>, argcount=<optimized out>, kwnames=0x0) at Python/ceval.c:2542
#15 0x0000555555e5be84 in builtin___build_class__ (self=<optimized out>, args=<optimized out>, nargs=2, kwnames=<optimized out>) at Python/bltinmodule.c:205
#16 0x0000555555e6ffcf in _Py_BuiltinCallFastWithKeywords_StackRefSteal (callable=..., arguments=<optimized out>, total_args=2) at Python/ceval.c:1181
#17 0x0000555555e8ff48 in _PyEval_EvalFrameDefault (tstate=<optimized out>, frame=<optimized out>, throwflag=<optimized out>) at Python/generated_cases.c.h:2287
#18 0x0000555555e6db18 in _PyEval_EvalFrame (tstate=0x555556e6afb0 <_PyRuntime+359376>, frame=0x7e8ff6fe5220, throwflag=0) at ./Include/internal/pycore_ceval.h:119
#19 _PyEval_Vector (tstate=<optimized out>, func=<optimized out>, locals=<optimized out>, args=<optimized out>, argcount=<optimized out>, kwnames=0x0) at Python/ceval.c:2542
#20 0x0000555555e6d535 in PyEval_EvalCode (co=<optimized out>, globals=<optimized out>, locals=0x7c7ff7086540) at Python/ceval.c:1008
Output from running with PYTHON_LLTRACE=4 PYTHON_OPT_DEBUG=4:
2492_abort_lltrace_opt_debug.txt
Found using lafleur.
CPython versions tested on:
CPython main branch
Operating systems tested on:
Linux
Output from running 'python -VV' on the command line:
Python 3.15.0a3+ (heads/main-dirty:cc48bf0fde8, Dec 24 2025, 22:16:25) [Clang 21.1.2 (2ubuntu6)]