[CI - macos] Fatal python error during wheel validation

[mitchdz]

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Describe the bug

Might be related to #3900.

https://github.com/NVIDIA/cuda-quantum/actions/runs/21905623782/job/63249815275#step:5:1503

Fatal Python error: Aborted

build/validation/tests/remote/test_remote_platform.py::test_multi_qpus Running backend tests.
Thread 0x00000001f6bfac40 (most recent call first):
  File "/Users/runner/work/cuda-quantum/cuda-quantum/build/validation/tests/remote/test_remote_platform.py", line 156 in opt_gradient
  File "/Users/runner/work/cuda-quantum/cuda-quantum/build/validation/tests/remote/test_remote_platform.py", line 162 in check_multi_qpus
  File "/Users/runner/work/cuda-quantum/cuda-quantum/build/validation/tests/remote/test_remote_platform.py", line 180 in test_multi_qpus
  File "/Users/runner/.venv/cudaq-validation/lib/python3.12/site-packages/_pytest/python.py", line 159 in pytest_pyfunc_call
  File "/Users/runner/.venv/cudaq-validation/lib/python3.12/site-packages/pluggy/_callers.py", line 121 in _multicall
  File "/Users/runner/.venv/cudaq-validation/lib/python3.12/site-packages/pluggy/_manager.py", line 120 in _hookexec
  File "/Users/runner/.venv/cudaq-validation/lib/python3.12/site-packages/pluggy/_hooks.py", line 512 in __call__
  File "/Users/runner/.venv/cudaq-validation/lib/python3.12/site-packages/_pytest/python.py", line 1627 in runtest
  File "/Users/runner/.venv/cudaq-validation/lib/python3.12/site-packages/_pytest/runner.py", line 174 in pytest_runtest_call
  File "/Users/runner/.venv/cudaq-validation/lib/python3.12/site-packages/pluggy/_callers.py", line 121 in _multicall
  File "/Users/runner/.venv/cudaq-validation/lib/python3.12/site-packages/pluggy/_manager.py", line 120 in _hookexec
  File "/Users/runner/.venv/cudaq-validation/lib/python3.12/site-packages/pluggy/_hooks.py", line 512 in __call__
  File "/Users/runner/.venv/cudaq-validation/lib/python3.12/site-packages/_pytest/runner.py", line 242 in <lambda>
  File "/Users/runner/.venv/cudaq-validation/lib/python3.12/site-packages/_pytest/runner.py", line 341 in from_call
  File "/Users/runner/.venv/cudaq-validation/lib/python3.12/site-packages/_pytest/runner.py", line 241 in call_and_report
  File "/Users/runner/.venv/cudaq-validation/lib/python3.12/site-packages/_pytest/runner.py", line 132 in runtestprotocol
  File "/Users/runner/.venv/cudaq-validation/lib/python3.12/site-packages/_pytest/runner.py", line 113 in pytest_runtest_protocol
  File "/Users/runner/.venv/cudaq-validation/lib/python3.12/site-packages/pluggy/_callers.py", line 121 in _multicall
  File "/Users/runner/.venv/cudaq-validation/lib/python3.12/site-packages/pluggy/_manager.py", line 120 in _hookexec
  File "/Users/runner/.venv/cudaq-validation/lib/python3.12/site-packages/pluggy/_hooks.py", line 512 in __call__
  File "/Users/runner/.venv/cudaq-validation/lib/python3.12/site-packages/_pytest/main.py", line 362 in pytest_runtestloop
  File "/Users/runner/.venv/cudaq-validation/lib/python3.12/site-packages/pluggy/_callers.py", line 121 in _multicall
  File "/Users/runner/.venv/cudaq-validation/lib/python3.12/site-packages/pluggy/_manager.py", line 120 in _hookexec
  File "/Users/runner/.venv/cudaq-validation/lib/python3.12/site-packages/pluggy/_hooks.py", line 512 in __call__
  File "/Users/runner/.venv/cudaq-validation/lib/python3.12/site-packages/_pytest/main.py", line 337 in _main
  File "/Users/runner/.venv/cudaq-validation/lib/python3.12/site-packages/_pytest/main.py", line 283 in wrap_session
  File "/Users/runner/.venv/cudaq-validation/lib/python3.12/site-packages/_pytest/main.py", line 330 in pytest_cmdline_main
  File "/Users/runner/.venv/cudaq-validation/lib/python3.12/site-packages/pluggy/_callers.py", line 121 in _multicall
  File "/Users/runner/.venv/cudaq-validation/lib/python3.12/site-packages/pluggy/_manager.py", line 120 in _hookexec
  File "/Users/runner/.venv/cudaq-validation/lib/python3.12/site-packages/pluggy/_hooks.py", line 512 in __call__
  File "/Users/runner/.venv/cudaq-validation/lib/python3.12/site-packages/_pytest/config/__init__.py", line 175 in main
  File "/Users/runner/.venv/cudaq-validation/lib/python3.12/site-packages/_pytest/config/__init__.py", line 201 in console_main
  File "/Users/runner/.venv/cudaq-validation/lib/python3.12/site-packages/pytest/__main__.py", line 9 in <module>
  File "<frozen runpy>", line 88 in _run_code
  File "<frozen runpy>", line 198 in _run_module_as_main

Extension modules: numpy.core._multiarray_umath, numpy.core._multiarray_tests, numpy.linalg._umath_linalg, numpy.fft._pocketfft_internal, numpy.random._common, numpy.random.bit_generator, numpy.random._bounded_integers, numpy.random._mt19937, numpy.random.mtrand, numpy.random._philox, numpy.random._pcg64, numpy.random._sfc64, numpy.random._generator, scipy._lib._ccallback_c, scipy.special._ufuncs_cxx, scipy.special._ellip_harm_2, scipy.special._special_ufuncs, scipy.special._gufuncs, scipy.special._ufuncs, scipy.special._specfun, scipy.special._comb, scipy.linalg._fblas, scipy.linalg._flapack, _cyutility, scipy._cyutility, scipy.linalg.cython_lapack, scipy.linalg._cythonized_array_utils, scipy.linalg._solve_toeplitz, scipy.linalg._decomp_lu_cython, scipy.linalg._matfuncs_schur_sqrtm, scipy.linalg._matfuncs_expm, scipy.linalg._linalg_pythran, scipy.linalg.cython_blas, scipy.linalg._decomp_update, scipy.sparse._sparsetools, _csparsetools, scipy.sparse._csparsetools, scipy.integrate._odepack, scipy.integrate._quadpack, scipy.integrate._vode, scipy.integrate._dop, scipy.integrate._lsoda, scipy.sparse.linalg._dsolve._superlu, scipy.sparse.linalg._eigen.arpack._arpack, scipy.sparse.linalg._propack._spropack, scipy.sparse.linalg._propack._dpropack, scipy.sparse.linalg._propack._cpropack, scipy.sparse.linalg._propack._zpropack, scipy.optimize._group_columns, scipy._lib.messagestream, scipy.optimize._trlib._trlib, scipy.optimize._lbfgsb, _moduleTNC, scipy.optimize._moduleTNC, scipy.optimize._slsqplib, scipy.optimize._minpack, scipy.optimize._lsq.givens_elimination, scipy.optimize._zeros, scipy._lib._uarray._uarray, scipy.linalg._decomp_interpolative, scipy.optimize._bglu_dense, scipy.optimize._lsap, scipy.spatial._ckdtree, scipy.spatial._qhull, scipy.spatial._voronoi, scipy.spatial._hausdorff, scipy.spatial._distance_wrap, scipy.spatial.transform._rotation, scipy.spatial.transform._rigid_transform, scipy.optimize._direct (total: 70)
scripts/validate_pycudaq.sh: line 227:  1931 Abort trap: 6           python3 -m pytest -v "$root_folder/tests" --ignore "$root_folder/tests/backends" --ignore "$root_folder/tests/dynamics/integrators" --ignore "$root_folder/tests/parallel" --ignore "$root_folder/tests/domains"
\e[01;31mPython tests failed.\e[0m

Steps to reproduce the bug

N/A

Expected behavior

N/A

Is this a regression? If it is, put the last known working version (or commit) here.

Not a regression

Environment

• CUDA-Q version: fe1869a
• Python version: 3.12
• Operating system: arm64

Suggestions

No response

[taalexander]

This is an outcome of #3900. Was able to reproduce locally by killing a cudaq-qpud server mid-execution. The RestClient::post throws a std::runtime_error, but on macOS ARM64 the exception can't cross the JIT execution boundary (#3900), so libc++abi calls std::terminate instead of propagating it as a catchable Python error.

The transient connection errors on macOS CI runners are the cause but the JIT exception boundary bug is why it crashes instead of raising a RuntimeError. I will look to see why the processes are crashing.