NoSuchProcess in short-lived nodes (resouce monitoring)

[oesteban]

multiprocessing.pool.RemoteTraceback: 
"""
Traceback (most recent call last):
  File "/usr/local/miniconda/lib/python3.6/multiprocessing/pool.py", line 119, in worker
    result = (True, func(*args, **kwds))
  File "/usr/local/miniconda/lib/python3.6/multiprocessing/pool.py", line 44, in mapstar
    return list(map(*args))
  File "/usr/local/miniconda/lib/python3.6/site-packages/fmriprep/interfaces/itk.py", line 237, in _mat2itk
    fsl2ras=True, itk_transform=out_file).run()
  File "/usr/local/miniconda/lib/python3.6/site-packages/niworkflows/nipype/interfaces/base.py", line 1080, in run
    mon_sp = ResourceMonitor(proc_pid, freq=mon_freq)
  File "/usr/local/miniconda/lib/python3.6/site-packages/niworkflows/nipype/utils/profiler.py", line 50, in __init__
    self._sample(cpu_interval=0.2)
  File "/usr/local/miniconda/lib/python3.6/site-packages/niworkflows/nipype/utils/profiler.py", line 82, in _sample
    for child in self._process.children(recursive=True):
  File "/usr/local/miniconda/lib/python3.6/site-packages/psutil/__init__.py", line 362, in wrapper
    raise NoSuchProcess(self.pid, self._name)
psutil.NoSuchProcess: psutil.NoSuchProcess process no longer exists (pid=11094)
"""

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
  File "/usr/local/miniconda/lib/python3.6/site-packages/niworkflows/nipype/pipeline/plugins/multiproc.py", line 51, in run_node
    result['result'] = node.run(updatehash=updatehash)
  File "/usr/local/miniconda/lib/python3.6/site-packages/niworkflows/nipype/pipeline/engine/nodes.py", line 407, in run
    self._run_interface()
  File "/usr/local/miniconda/lib/python3.6/site-packages/niworkflows/nipype/pipeline/engine/nodes.py", line 517, in _run_interface
    self._result = self._run_command(execute)
  File "/usr/local/miniconda/lib/python3.6/site-packages/niworkflows/nipype/pipeline/engine/nodes.py", line 650, in _run_command
    result = self._interface.run()
  File "/usr/local/miniconda/lib/python3.6/site-packages/niworkflows/nipype/interfaces/base.py", line 1088, in run
    runtime = self._run_interface(runtime)
  File "/usr/local/miniconda/lib/python3.6/site-packages/fmriprep/interfaces/itk.py", line 62, in _run_interface
    for i, in_mat in enumerate(self.inputs.in_files)]
  File "/usr/local/miniconda/lib/python3.6/multiprocessing/pool.py", line 260, in map
    return self._map_async(func, iterable, mapstar, chunksize).get()
  File "/usr/local/miniconda/lib/python3.6/multiprocessing/pool.py", line 608, in get
    raise self._value
psutil.NoSuchProcess: psutil.NoSuchProcess process no longer exists (pid=11094)