docker - "az vmss scale" fails with "can't start new thread" #32173

root [ / ]# az vmss scale --resource-group MyGroup --name myVmss --new-capacity 6
The command failed with an unexpected error. Here is the traceback:
can't start new thread
Traceback (most recent call last):
  File "/usr/lib64/az/lib/python3.12/site-packages/knack/cli.py", line 233, in invoke
    cmd_result = self.invocation.execute(args)
                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/lib64/az/lib/python3.12/site-packages/azure/cli/core/commands/__init__.py", line 666, in execute
    raise ex
  File "/usr/lib64/az/lib/python3.12/site-packages/azure/cli/core/commands/__init__.py", line 734, in _run_jobs_serially
    results.append(self._run_job(expanded_arg, cmd_copy))
                   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/lib64/az/lib/python3.12/site-packages/azure/cli/core/commands/__init__.py", line 703, in _run_job
    result = cmd_copy(params)
             ^^^^^^^^^^^^^^^^
  File "/usr/lib64/az/lib/python3.12/site-packages/azure/cli/core/commands/__init__.py", line 336, in __call__
    return self.handler(*args, **kwargs)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/lib64/az/lib/python3.12/site-packages/azure/cli/core/commands/command_operation.py", line 120, in handler
    return op(**command_args)
           ^^^^^^^^^^^^^^^^^^
  File "/usr/lib64/az/lib/python3.12/site-packages/azure/cli/command_modules/vm/custom.py", line 4035, in scale_vmss
    return sdk_no_wait(no_wait, client.virtual_machine_scale_sets.begin_create_or_update,
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/lib64/az/lib/python3.12/site-packages/azure/cli/core/util.py", line 759, in sdk_no_wait
    return func(*args, **kwargs)
           ^^^^^^^^^^^^^^^^^^^^^
  File "/usr/lib64/az/lib/python3.12/site-packages/azure/core/tracing/decorator.py", line 119, in wrapper_use_tracer
    return func(*args, **kwargs)
           ^^^^^^^^^^^^^^^^^^^^^
  File "/usr/lib64/az/lib/python3.12/site-packages/azure/mgmt/compute/v2024_11_01/operations/_operations.py", line 7076, in begin_create_or_update
    return LROPoller[_models.VirtualMachineScaleSet](
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/lib/python3.12/typing.py", line 1184, in __call__
    result = self.__origin__(*args, **kwargs)
             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/lib64/az/lib/python3.12/site-packages/azure/core/polling/_poller.py", line 243, in __init__
    self._thread.start()
  File "/usr/lib/python3.12/threading.py", line 994, in start
    _start_new_thread(self._bootstrap, ())
RuntimeError: can't start new thread