CI, TST: pre-release failures for scipy/interpolate/tests/test_rbfinterp.py

This failure is showing up all over the place for Azure Pipelines pre-release runs. I don’t know if this is just a blip because of a bleeding edge dependency, but it seems like the test suite produces a segfault after getting to 10-20 % progress and produces a traceback like the one below the fold. The traceback is so ridiculously long that I’ll just mention that scipy/interpolate/tests/test_rbfinterp.py", line 375 in test_pickleable shows up in there.

021-09-13T14:01:27.8800593Z ..................................Fatal Python error: Segmentation fault
2021-09-13T14:01:27.8801755Z 
2021-09-13T14:01:27.8804483Z Thread 0x00007fcb59a6a700 (most recent call first):
2021-09-13T14:01:27.8840916Z   File "/opt/hostedtoolcache/Python/3.9.6/x64/lib/python3.9/site-packages/execnet/gateway_base.py", line 400 in read
2021-09-13T14:01:27.8878458Z   File "/opt/hostedtoolcache/Python/3.9.6/x64/lib/python3.9/site-packages/execnet/gateway_base.py", line 432 in from_io
2021-09-13T14:01:27.8923939Z   File "/opt/hostedtoolcache/Python/3.9.6/x64/lib/python3.9/site-packages/execnet/gateway_base.py", line 967 in _thread_receiver
2021-09-13T14:01:27.8953482Z   File "/opt/hostedtoolcache/Python/3.9.6/x64/lib/python3.9/site-packages/execnet/gateway_base.py", line 220 in run
2021-09-13T14:01:27.8968135Z   File "/opt/hostedtoolcache/Python/3.9.6/x64/lib/python3.9/site-packages/execnet/gateway_base.py", line 285 in _perform_spawn
2021-09-13T14:01:27.8968990Z 
2021-09-13T14:01:27.8969615Z Current thread 0x00007fcb5c500740 (most recent call first):
2021-09-13T14:01:27.8984911Z   File "/home/vsts/work/1/s/build/testenv/lib/python3.9/site-packages/scipy/interpolate/tests/test_rbfinterp.py", line 375 in test_pickleable
2021-09-13T14:01:27.8998727Z   File "/opt/hostedtoolcache/Python/3.9.6/x64/lib/python3.9/site-packages/_pytest/python.py", line 183 in pytest_pyfunc_call
2021-09-13T14:01:27.9036114Z   File "/opt/hostedtoolcache/Python/3.9.6/x64/lib/python3.9/site-packages/pluggy/_callers.py", line 39 in _multicall
2021-09-13T14:01:27.9037394Z   File "/opt/hostedtoolcache/Python/3.9.6/x64/lib/python3.9/site-packages/pluggy/_manager.py", line 80 in _hookexec
2021-09-13T14:01:27.9038435Z   File "/opt/hostedtoolcache/Python/3.9.6/x64/lib/python3.9/site-packages/pluggy/_hooks.py", line 265 in __call__
2021-09-13T14:01:27.9039475Z   File "/opt/hostedtoolcache/Python/3.9.6/x64/lib/python3.9/site-packages/_pytest/python.py", line 1641 in runtest
2021-09-13T14:01:27.9040539Z   File "/opt/hostedtoolcache/Python/3.9.6/x64/lib/python3.9/site-packages/_pytest/runner.py", line 162 in pytest_runtest_call
2021-09-13T14:01:27.9041568Z   File "/opt/hostedtoolcache/Python/3.9.6/x64/lib/python3.9/site-packages/pluggy/_callers.py", line 39 in _multicall
2021-09-13T14:01:27.9042598Z   File "/opt/hostedtoolcache/Python/3.9.6/x64/lib/python3.9/site-packages/pluggy/_manager.py", line 80 in _hookexec
2021-09-13T14:01:27.9043618Z   File "/opt/hostedtoolcache/Python/3.9.6/x64/lib/python3.9/site-packages/pluggy/_hooks.py", line 265 in __call__
2021-09-13T14:01:27.9044631Z   File "/opt/hostedtoolcache/Python/3.9.6/x64/lib/python3.9/site-packages/_pytest/runner.py", line 255 in <lambda>
2021-09-13T14:01:27.9045653Z   File "/opt/hostedtoolcache/Python/3.9.6/x64/lib/python3.9/site-packages/_pytest/runner.py", line 311 in from_call
2021-09-13T14:01:27.9046690Z   File "/opt/hostedtoolcache/Python/3.9.6/x64/lib/python3.9/site-packages/_pytest/runner.py", line 254 in call_runtest_hook
2021-09-13T14:01:27.9047737Z   File "/opt/hostedtoolcache/Python/3.9.6/x64/lib/python3.9/site-packages/_pytest/runner.py", line 215 in call_and_report
2021-09-13T14:01:27.9048803Z   File "/opt/hostedtoolcache/Python/3.9.6/x64/lib/python3.9/site-packages/_pytest/runner.py", line 126 in runtestprotocol
2021-09-13T14:01:27.9049867Z   File "/opt/hostedtoolcache/Python/3.9.6/x64/lib/python3.9/site-packages/_pytest/runner.py", line 109 in pytest_runtest_protocol
2021-09-13T14:01:27.9050898Z   File "/opt/hostedtoolcache/Python/3.9.6/x64/lib/python3.9/site-packages/pluggy/_callers.py", line 39 in _multicall
2021-09-13T14:01:27.9052265Z   File "/opt/hostedtoolcache/Python/3.9.6/x64/lib/python3.9/site-packages/pluggy/_manager.py", line 80 in _hookexec
2021-09-13T14:01:27.9053313Z   File "/opt/hostedtoolcache/Python/3.9.6/x64/lib/python3.9/site-packages/pluggy/_hooks.py", line 265 in __call__
2021-09-13T14:01:27.9054353Z   File "/opt/hostedtoolcache/Python/3.9.6/x64/lib/python3.9/site-packages/xdist/remote.py", line 89 in run_one_test
2021-09-13T14:01:27.9055398Z   File "/opt/hostedtoolcache/Python/3.9.6/x64/lib/python3.9/site-packages/xdist/remote.py", line 72 in pytest_runtestloop
2021-09-13T14:01:27.9056434Z   File "/opt/hostedtoolcache/Python/3.9.6/x64/lib/python3.9/site-packages/pluggy/_callers.py", line 39 in _multicall
2021-09-13T14:01:27.9057455Z   File "/opt/hostedtoolcache/Python/3.9.6/x64/lib/python3.9/site-packages/pluggy/_manager.py", line 80 in _hookexec
2021-09-13T14:01:27.9058465Z   File "/opt/hostedtoolcache/Python/3.9.6/x64/lib/python3.9/site-packages/pluggy/_hooks.py", line 265 in __call__
2021-09-13T14:01:27.9059480Z   File "/opt/hostedtoolcache/Python/3.9.6/x64/lib/python3.9/site-packages/_pytest/main.py", line 323 in _main
2021-09-13T14:01:27.9061168Z   File "/opt/hostedtoolcache/Python/3.9.6/x64/lib/python3.9/site-packages/_pytest/main.py", line 269 in wrap_session
2021-09-13T14:01:27.9063322Z   File "/opt/hostedtoolcache/Python/3.9.6/x64/lib/python3.9/site-packages/_pytest/main.py", line 316 in pytest_cmdline_main
2021-09-13T14:01:27.9064356Z   File "/opt/hostedtoolcache/Python/3.9.6/x64/lib/python3.9/site-packages/pluggy/_callers.py", line 39 in _multicall
2021-09-13T14:01:27.9065181Z   File "/opt/hostedtoolcache/Python/3.9.6/x64/lib/python3.9/site-packages/pluggy/_manager.py", line 80 in _hookexec
2021-09-13T14:01:27.9065987Z   File "/opt/hostedtoolcache/Python/3.9.6/x64/lib/python3.9/site-packages/pluggy/_hooks.py", line 265 in __call__
2021-09-13T14:01:27.9066802Z   File "/opt/hostedtoolcache/Python/3.9.6/x64/lib/python3.9/site-packages/xdist/remote.py", line 246 in <module>
2021-09-13T14:01:27.9067633Z   File "/opt/hostedtoolcache/Python/3.9.6/x64/lib/python3.9/site-packages/execnet/gateway_base.py", line 1084 in executetask
2021-09-13T14:01:27.9068470Z   File "/opt/hostedtoolcache/Python/3.9.6/x64/lib/python3.9/site-packages/execnet/gateway_base.py", line 220 in run
2021-09-13T14:01:27.9069320Z   File "/opt/hostedtoolcache/Python/3.9.6/x64/lib/python3.9/site-packages/execnet/gateway_base.py", line 285 in _perform_spawn
2021-09-13T14:01:27.9070197Z   File "/opt/hostedtoolcache/Python/3.9.6/x64/lib/python3.9/site-packages/execnet/gateway_base.py", line 267 in integrate_as_primary_thread
2021-09-13T14:01:27.9071060Z   File "/opt/hostedtoolcache/Python/3.9.6/x64/lib/python3.9/site-packages/execnet/gateway_base.py", line 1060 in serve
2021-09-13T14:01:27.9071915Z   File "/opt/hostedtoolcache/Python/3.9.6/x64/lib/python3.9/site-packages/execnet/gateway_base.py", line 1554 in serve
2021-09-13T14:01:27.9072416Z   File "<string>", line 8 in <module>
2021-09-13T14:01:27.9072803Z   File "<string>", line 1 in <module>
2021-09-13T14:01:31.7185684Z ...................................... [ 18%]
2021-09-13T14:01:33.9471894Z ......................Fatal Python error: Segmentation fault
2021-09-13T14:01:33.9472980Z 
2021-09-13T14:01:33.9475827Z Thread 0x00007fac1e72d700 (most recent call first):
2021-09-13T14:01:33.9511865Z   File "/opt/hostedtoolcache/Python/3.9.6/x64/lib/python3.9/site-packages/execnet/gateway_base.py", line 400 in read
2021-09-13T14:01:33.9548936Z   File "/opt/hostedtoolcache/Python/3.9.6/x64/lib/python3.9/site-packages/execnet/gateway_base.py", line 432 in from_io
2021-09-13T14:01:33.9590154Z   File "/opt/hostedtoolcache/Python/3.9.6/x64/lib/python3.9/site-packages/execnet/gateway_base.py", line 967 in _thread_receiver
2021-09-13T14:01:33.9625413Z   File "/opt/hostedtoolcache/Python/3.9.6/x64/lib/python3.9/site-packages/execnet/gateway_base.py", line 220 in run
2021-09-13T14:01:33.9639383Z   File "/opt/hostedtoolcache/Python/3.9.6/x64/lib/python3.9/site-packages/execnet/gateway_base.py", line 285 in _perform_spawn
2021-09-13T14:01:33.9640000Z 
2021-09-13T14:01:33.9642259Z Current thread 0x00007fac211c3740 (most recent call first):
2021-09-13T14:01:33.9657477Z   File "/home/vsts/work/1/s/build/testenv/lib/python3.9/site-packages/scipy/interpolate/tests/test_rbfinterp.py", line 375 in test_pickleable
2021-09-13T14:01:33.9671669Z   File "/opt/hostedtoolcache/Python/3.9.6/x64/lib/python3.9/site-packages/_pytest/python.py", line 183 in pytest_pyfunc_call
2021-09-13T14:01:33.9684293Z   File "/opt/hostedtoolcache/Python/3.9.6/x64/lib/python3.9/site-packages/pluggy/_callers.py", line 39 in _multicall
2021-09-13T14:01:33.9699364Z   File "/opt/hostedtoolcache/Python/3.9.6/x64/lib/python3.9/site-packages/pluggy/_manager.py", line 80 in _hookexec
2021-09-13T14:01:33.9700493Z   File "/opt/hostedtoolcache/Python/3.9.6/x64/lib/python3.9/site-packages/pluggy/_hooks.py", line 265 in __call__
2021-09-13T14:01:33.9701486Z   File "/opt/hostedtoolcache/Python/3.9.6/x64/lib/python3.9/site-packages/_pytest/python.py", line 1641 in runtest
2021-09-13T14:01:33.9702507Z   File "/opt/hostedtoolcache/Python/3.9.6/x64/lib/python3.9/site-packages/_pytest/runner.py", line 162 in pytest_runtest_call
2021-09-13T14:01:33.9703467Z   File "/opt/hostedtoolcache/Python/3.9.6/x64/lib/python3.9/site-packages/pluggy/_callers.py", line 39 in _multicall
2021-09-13T14:01:33.9704427Z   File "/opt/hostedtoolcache/Python/3.9.6/x64/lib/python3.9/site-packages/pluggy/_manager.py", line 80 in _hookexec
2021-09-13T14:01:33.9705595Z   File "/opt/hostedtoolcache/Python/3.9.6/x64/lib/python3.9/site-packages/pluggy/_hooks.py", line 265 in __call__
2021-09-13T14:01:33.9706529Z   File "/opt/hostedtoolcache/Python/3.9.6/x64/lib/python3.9/site-packages/_pytest/runner.py", line 255 in <lambda>
2021-09-13T14:01:33.9707488Z   File "/opt/hostedtoolcache/Python/3.9.6/x64/lib/python3.9/site-packages/_pytest/runner.py", line 311 in from_call
2021-09-13T14:01:33.9708463Z   File "/opt/hostedtoolcache/Python/3.9.6/x64/lib/python3.9/site-packages/_pytest/runner.py", line 254 in call_runtest_hook
2021-09-13T14:01:33.9709454Z   File "/opt/hostedtoolcache/Python/3.9.6/x64/lib/python3.9/site-packages/_pytest/runner.py", line 215 in call_and_report
2021-09-13T14:01:33.9710409Z   File "/opt/hostedtoolcache/Python/3.9.6/x64/lib/python3.9/site-packages/_pytest/runner.py", line 126 in runtestprotocol
2021-09-13T14:01:33.9711399Z   File "/opt/hostedtoolcache/Python/3.9.6/x64/lib/python3.9/site-packages/_pytest/runner.py", line 109 in pytest_runtest_protocol
2021-09-13T14:01:33.9712390Z   File "/opt/hostedtoolcache/Python/3.9.6/x64/lib/python3.9/site-packages/pluggy/_callers.py", line 39 in _multicall
2021-09-13T14:01:33.9715682Z   File "/opt/hostedtoolcache/Python/3.9.6/x64/lib/python3.9/site-packages/pluggy/_manager.py", line 80 in _hookexec
2021-09-13T14:01:33.9745464Z   File "/opt/hostedtoolcache/Python/3.9.6/x64/lib/python3.9/site-packages/pluggy/_hooks.py", line 265 in __call__
2021-09-13T14:01:33.9758706Z   File "/opt/hostedtoolcache/Python/3.9.6/x64/lib/python3.9/site-packages/xdist/remote.py", line 89 in run_one_test
2021-09-13T14:01:33.9781599Z   File "/opt/hostedtoolcache/Python/3.9.6/x64/lib/python3.9/site-packages/xdist/remote.py", line 72 in pytest_runtestloop
2021-09-13T14:01:33.9782740Z   File "/opt/hostedtoolcache/Python/3.9.6/x64/lib/python3.9/site-packages/pluggy/_callers.py", line 39 in _multicall
2021-09-13T14:01:33.9783714Z   File "/opt/hostedtoolcache/Python/3.9.6/x64/lib/python3.9/site-packages/pluggy/_manager.py", line 80 in _hookexec
2021-09-13T14:01:33.9784696Z   File "/opt/hostedtoolcache/Python/3.9.6/x64/lib/python3.9/site-packages/pluggy/_hooks.py", line 265 in __call__
2021-09-13T14:01:33.9785642Z   File "/opt/hostedtoolcache/Python/3.9.6/x64/lib/python3.9/site-packages/_pytest/main.py", line 323 in _main
2021-09-13T14:01:33.9786595Z   File "/opt/hostedtoolcache/Python/3.9.6/x64/lib/python3.9/site-packages/_pytest/main.py", line 269 in wrap_session
2021-09-13T14:01:33.9787701Z   File "/opt/hostedtoolcache/Python/3.9.6/x64/lib/python3.9/site-packages/_pytest/main.py", line 316 in pytest_cmdline_main
2021-09-13T14:01:33.9788675Z   File "/opt/hostedtoolcache/Python/3.9.6/x64/lib/python3.9/site-packages/pluggy/_callers.py", line 39 in _multicall
2021-09-13T14:01:33.9789625Z   File "/opt/hostedtoolcache/Python/3.9.6/x64/lib/python3.9/site-packages/pluggy/_manager.py", line 80 in _hookexec
2021-09-13T14:01:33.9790557Z   File "/opt/hostedtoolcache/Python/3.9.6/x64/lib/python3.9/site-packages/pluggy/_hooks.py", line 265 in __call__
2021-09-13T14:01:33.9791513Z   File "/opt/hostedtoolcache/Python/3.9.6/x64/lib/python3.9/site-packages/xdist/remote.py", line 246 in <module>
2021-09-13T14:01:33.9792482Z   File "/opt/hostedtoolcache/Python/3.9.6/x64/lib/python3.9/site-packages/execnet/gateway_base.py", line 1084 in executetask
2021-09-13T14:01:33.9793428Z   File "/opt/hostedtoolcache/Python/3.9.6/x64/lib/python3.9/site-packages/execnet/gateway_base.py", line 220 in run
2021-09-13T14:01:33.9794406Z   File "/opt/hostedtoolcache/Python/3.9.6/x64/lib/python3.9/site-packages/execnet/gateway_base.py", line 285 in _perform_spawn
2021-09-13T14:01:33.9795417Z   File "/opt/hostedtoolcache/Python/3.9.6/x64/lib/python3.9/site-packages/execnet/gateway_base.py", line 267 in integrate_as_primary_thread
2021-09-13T14:01:33.9796405Z   File "/opt/hostedtoolcache/Python/3.9.6/x64/lib/python3.9/site-packages/execnet/gateway_base.py", line 1060 in serve
2021-09-13T14:01:33.9797460Z   File "/opt/hostedtoolcache/Python/3.9.6/x64/lib/python3.9/site-packages/execnet/gateway_base.py", line 1554 in serve
2021-09-13T14:01:33.9798098Z   File "<string>", line 8 in <module>
2021-09-13T14:01:33.9798601Z   File "<string>", line 1 in <module>
2021-09-13T14:02:04.1134287Z [gw1] node down: Not properly terminated
2021-09-13T14:02:16.2967625Z INTERNALERROR> Traceback (most recent call last):
2021-09-13T14:02:16.2969704Z INTERNALERROR>   File "/opt/hostedtoolcache/Python/3.9.6/x64/lib/python3.9/site-packages/execnet/gateway_base.py", line 997, in _send
2021-09-13T14:02:16.2972387Z INTERNALERROR>     message.to_io(self._io)
2021-09-13T14:02:16.2973766Z INTERNALERROR>   File "/opt/hostedtoolcache/Python/3.9.6/x64/lib/python3.9/site-packages/execnet/gateway_base.py", line 443, in to_io
2021-09-13T14:02:16.2974482Z INTERNALERROR>     io.write(header + self.data)
2021-09-13T14:02:16.2975389Z INTERNALERROR>   File "/opt/hostedtoolcache/Python/3.9.6/x64/lib/python3.9/site-packages/execnet/gateway_base.py", line 409, in write
2021-09-13T14:02:16.2976118Z INTERNALERROR>     self._write(data)
2021-09-13T14:02:16.2976676Z INTERNALERROR> BrokenPipeError: [Errno 32] Broken pipe
2021-09-13T14:02:16.2977196Z INTERNALERROR> 
2021-09-13T14:02:16.2977769Z INTERNALERROR> During handling of the above exception, another exception occurred:
2021-09-13T14:02:16.2978346Z INTERNALERROR> 
2021-09-13T14:02:16.2978848Z INTERNALERROR> Traceback (most recent call last):
2021-09-13T14:02:16.2979771Z INTERNALERROR>   File "/opt/hostedtoolcache/Python/3.9.6/x64/lib/python3.9/site-packages/_pytest/main.py", line 269, in wrap_session
2021-09-13T14:02:16.2980481Z INTERNALERROR>     session.exitstatus = doit(config, session) or 0
2021-09-13T14:02:16.2981403Z INTERNALERROR>   File "/opt/hostedtoolcache/Python/3.9.6/x64/lib/python3.9/site-packages/_pytest/main.py", line 323, in _main
2021-09-13T14:02:16.2982508Z INTERNALERROR>     config.hook.pytest_runtestloop(session=session)
2021-09-13T14:02:16.2983463Z INTERNALERROR>   File "/opt/hostedtoolcache/Python/3.9.6/x64/lib/python3.9/site-packages/pluggy/_hooks.py", line 265, in __call__
2021-09-13T14:02:16.2984197Z INTERNALERROR>     return self._hookexec(self.name, self.get_hookimpls(), kwargs, firstresult)
2021-09-13T14:02:16.2985145Z INTERNALERROR>   File "/opt/hostedtoolcache/Python/3.9.6/x64/lib/python3.9/site-packages/pluggy/_manager.py", line 80, in _hookexec
2021-09-13T14:02:16.2985875Z INTERNALERROR>     return self._inner_hookexec(hook_name, methods, kwargs, firstresult)
2021-09-13T14:02:16.2987454Z INTERNALERROR>   File "/opt/hostedtoolcache/Python/3.9.6/x64/lib/python3.9/site-packages/pluggy/_callers.py", line 60, in _multicall
2021-09-13T14:02:16.2988292Z INTERNALERROR>     return outcome.get_result()
2021-09-13T14:02:16.2989675Z INTERNALERROR>   File "/opt/hostedtoolcache/Python/3.9.6/x64/lib/python3.9/site-packages/pluggy/_result.py", line 60, in get_result
2021-09-13T14:02:16.2990424Z INTERNALERROR>     raise ex[1].with_traceback(ex[2])
2021-09-13T14:02:16.2991335Z INTERNALERROR>   File "/opt/hostedtoolcache/Python/3.9.6/x64/lib/python3.9/site-packages/pluggy/_callers.py", line 39, in _multicall
2021-09-13T14:02:16.2992073Z INTERNALERROR>     res = hook_impl.function(*args)
2021-09-13T14:02:16.2992972Z INTERNALERROR>   File "/opt/hostedtoolcache/Python/3.9.6/x64/lib/python3.9/site-packages/xdist/dsession.py", line 112, in pytest_runtestloop
2021-09-13T14:02:16.2993723Z INTERNALERROR>     self.loop_once()
2021-09-13T14:02:16.2995230Z INTERNALERROR>   File "/opt/hostedtoolcache/Python/3.9.6/x64/lib/python3.9/site-packages/xdist/dsession.py", line 135, in loop_once
2021-09-13T14:02:16.2995776Z INTERNALERROR>     call(**kwargs)
2021-09-13T14:02:16.2996527Z INTERNALERROR>   File "/opt/hostedtoolcache/Python/3.9.6/x64/lib/python3.9/site-packages/xdist/dsession.py", line 199, in worker_errordown
2021-09-13T14:02:16.2997163Z INTERNALERROR>     crashitem = self.sched.remove_node(node)
2021-09-13T14:02:16.2997938Z INTERNALERROR>   File "/opt/hostedtoolcache/Python/3.9.6/x64/lib/python3.9/site-packages/xdist/scheduler/load.py", line 215, in remove_node
2021-09-13T14:02:16.2998643Z INTERNALERROR>     self.check_schedule(node)
2021-09-13T14:02:16.2999410Z INTERNALERROR>   File "/opt/hostedtoolcache/Python/3.9.6/x64/lib/python3.9/site-packages/xdist/scheduler/load.py", line 188, in check_schedule
2021-09-13T14:02:16.2999988Z INTERNALERROR>     self._send_tests(node, num_send)
2021-09-13T14:02:16.3000760Z INTERNALERROR>   File "/opt/hostedtoolcache/Python/3.9.6/x64/lib/python3.9/site-packages/xdist/scheduler/load.py", line 269, in _send_tests
2021-09-13T14:02:16.3001318Z INTERNALERROR>     node.send_runtest_some(tests_per_node)
2021-09-13T14:02:16.3002142Z INTERNALERROR>   File "/opt/hostedtoolcache/Python/3.9.6/x64/lib/python3.9/site-packages/xdist/workermanage.py", line 284, in send_runtest_some
2021-09-13T14:02:16.3002747Z INTERNALERROR>     self.sendcommand("runtests", indices=indices)
2021-09-13T14:02:16.3003543Z INTERNALERROR>   File "/opt/hostedtoolcache/Python/3.9.6/x64/lib/python3.9/site-packages/xdist/workermanage.py", line 300, in sendcommand
2021-09-13T14:02:16.3004106Z INTERNALERROR>     self.channel.send((name, kwargs))
2021-09-13T14:02:16.3004844Z INTERNALERROR>   File "/opt/hostedtoolcache/Python/3.9.6/x64/lib/python3.9/site-packages/execnet/gateway_base.py", line 729, in send
2021-09-13T14:02:16.3005448Z INTERNALERROR>     self.gateway._send(Message.CHANNEL_DATA, self.id, dumps_internal(item))
2021-09-13T14:02:16.3006258Z INTERNALERROR>   File "/opt/hostedtoolcache/Python/3.9.6/x64/lib/python3.9/site-packages/execnet/gateway_base.py", line 1003, in _send
2021-09-13T14:02:16.3006853Z INTERNALERROR>     raise IOError("cannot send (already closed?)")
2021-09-13T14:02:16.3007329Z INTERNALERROR> OSError: cannot send (already closed?)
2021-09-13T14:02:16.3042855Z 
2021-09-13T14:02:16.3064907Z ============ 6569 passed, 6 skipped, 2 xfailed in 166.36s (0:02:46) ============

[da-woods]

Next thought - does np.import_array() (placed as soon as possible after cimport numpy) fix it? It’s possible that PyArray_SIZE might require the Numpy API to be initialized whereas the old direct access intp PyArrayObject didn’t.

If so it probably exposes a (minor) Cython bug - Cython now tries to auto-add np.import_array in-case you forget it. Perhaps the standardization of the header guards broke that though.

---

Edit: I’m increasingly sure that’s it - Cython uses NPY_NDARRAYOBJECT_H as an indicator that the actual Numpy headers have been included when deciding to generate the code, and that’s obviously been renamed.

I’ll submit a fix to Cython. But in principle almost anywhere Scipy uses cimport numpy should be accompanied by a numpy.import_array() - Cython is making a best effort attempt to help you out but still thinks it’s really your responsibility

[charris]

@seberg If this is only Cython 3 prereleases I’d be more inclined to fix Cython first, it just needs an | defined .... Header guards are nominally private, but Cython does seem like a reasonable exception to that rule. I suppose we could define both guards for the time being.