BlockingIOError: [Errno 35] Resource temporarily unavailable

[moreati]

Seen in CI on macOS 13 https://github.com/mitogen-hq/mitogen/actions/runs/11669080981/job/32490230504?pr=1176

TASK [Create /tmp/512mb.zero creates=/tmp/512mb.zero, _raw_params=dd if=/dev/zero of=/tmp/512mb.zero bs=1048576 count=512;
chmod go= /tmp/512mb.zero
] ***
Monday 04 November 2024  17:08:28 +0000 (0:00:00.007)       0:00:26.162 ******* 
changed: [target]
TASK [Fetch /tmp/512mb.zero src=/tmp/512mb.zero, dest=/tmp/fetch-{{ inventory_hostname }}-512mb.zero, flat=True] ***
Monday 04 November 2024  17:08:30 +0000 (0:00:01.338)       0:00:27.501 ******* 
ERROR! [mux  5271] 17:08:37.240824 E mitogen: <Stream unix_client.5683 #1dd0> crashed
Traceback (most recent call last):
  File "/Users/runner/work/mitogen/mitogen/mitogen/core.py", line 3677, in _call
    func(self)
    ~~~~^^^^^^
  File "/Users/runner/work/mitogen/mitogen/mitogen/core.py", line 1923, in on_transmit
    self.protocol.on_transmit(broker)
    ~~~~~~~~~~~~~~~~~~~~~~~~~^^^^^^^^
  File "/Users/runner/work/mitogen/mitogen/mitogen/core.py", line 2371, in on_transmit
    self._writer.on_transmit(broker)
    ~~~~~~~~~~~~~~~~~~~~~~~~^^^^^^^^
  File "/Users/runner/work/mitogen/mitogen/mitogen/core.py", line 2111, in on_transmit
    written = self._protocol.stream.transmit_side.write(buf)
  File "/Users/runner/work/mitogen/mitogen/mitogen/core.py", line 2237, in write
    written, disconnected = io_op(os.write, self.fd, s)
                            ~~~~~^^^^^^^^^^^^^^^^^^^^^^
  File "/Users/runner/work/mitogen/mitogen/mitogen/core.py", line 595, in io_op
    return func(*args), None
           ~~~~^^^^^^^
BlockingIOError: [Errno 35] Resource temporarily unavailable

Originally posted by @moreati in #1133 (comment)

[moreati]

Again https://github.com/mitogen-hq/mitogen/actions/runs/11700584431/job/32584889627

PLAY [regression/issue_615_streaming_transfer.yml] *****************************
TASK [include_tasks _raw_params=_mitogen_only.yml] *****************************
Wednesday 06 November 2024  09:20:58 +0000 (0:00:00.120)       0:00:26.685 **** 
included: /Users/runner/work/mitogen/mitogen/tests/ansible/regression/_mitogen_only.yml for target
TASK [meta _raw_params=end_play] ***********************************************
Wednesday 06 November 2024  09:20:58 +0000 (0:00:00.039)       0:00:26.725 **** 
skipping: [target]
TASK [Create /tmp/512mb.zero creates=/tmp/512mb.zero, _raw_params=dd if=/dev/zero of=/tmp/512mb.zero bs=1048576 count=512;
chmod go= /tmp/512mb.zero
] ***
Wednesday 06 November 2024  09:20:58 +0000 (0:00:00.014)       0:00:26.739 **** 
changed: [target]
TASK [Fetch /tmp/512mb.zero src=/tmp/512mb.zero, dest=/tmp/fetch-{{ inventory_hostname }}-512mb.zero, flat=True] ***
Wednesday 06 November 2024  09:21:00 +0000 (0:00:01.685)       0:00:28.424 **** 
ERROR! [mux  5601] 09:21:05.103152 E mitogen: <Stream unix_client.5949 #8cd0> crashed
Traceback (most recent call last):
  File "/Users/runner/work/mitogen/mitogen/mitogen/core.py", line 3677, in _call
    func(self)
    ~~~~^^^^^^
  File "/Users/runner/work/mitogen/mitogen/mitogen/core.py", line 1923, in on_transmit
    self.protocol.on_transmit(broker)
    ~~~~~~~~~~~~~~~~~~~~~~~~~^^^^^^^^
  File "/Users/runner/work/mitogen/mitogen/mitogen/core.py", line 2371, in on_transmit
    self._writer.on_transmit(broker)
    ~~~~~~~~~~~~~~~~~~~~~~~~^^^^^^^^
  File "/Users/runner/work/mitogen/mitogen/mitogen/core.py", line 2111, in on_transmit
    written = self._protocol.stream.transmit_side.write(buf)
  File "/Users/runner/work/mitogen/mitogen/mitogen/core.py", line 2237, in write
    written, disconnected = io_op(os.write, self.fd, s)
                            ~~~~~^^^^^^^^^^^^^^^^^^^^^^
  File "/Users/runner/work/mitogen/mitogen/mitogen/core.py", line 595, in io_op
    return func(*args), None
           ~~~~^^^^^^^
BlockingIOError: [Errno 35] Resource temporarily unavailable