Invalid file descriptor error after listing resources

[MauroPfister]

After a call to ResourceManager.list_resources() my script terminates with the following exception:

Exception ignored in: <function BaseEventLoop.__del__ at 0x7accb1c73250>
Traceback (most recent call last):
  File "/home/mauro/.pyenv/versions/3.10.7/lib/python3.10/asyncio/base_events.py", line 687, in __del__
    self.close()
  File "/home/mauro/.pyenv/versions/3.10.7/lib/python3.10/asyncio/unix_events.py", line 68, in close
    super().close()
  File "/home/mauro/.pyenv/versions/3.10.7/lib/python3.10/asyncio/selector_events.py", line 87, in close
    self._close_self_pipe()
  File "/home/mauro/.pyenv/versions/3.10.7/lib/python3.10/asyncio/selector_events.py", line 94, in _close_self_pipe
    self._remove_reader(self._ssock.fileno())
  File "/home/mauro/.pyenv/versions/3.10.7/lib/python3.10/asyncio/selector_events.py", line 272, in _remove_reader
    key = self._selector.get_key(fd)
  File "/home/mauro/.pyenv/versions/3.10.7/lib/python3.10/selectors.py", line 191, in get_key
    return mapping[fileobj]
  File "/home/mauro/.pyenv/versions/3.10.7/lib/python3.10/selectors.py", line 72, in __getitem__
    fd = self._selector._fileobj_lookup(fileobj)
  File "/home/mauro/.pyenv/versions/3.10.7/lib/python3.10/selectors.py", line 226, in _fileobj_lookup
    return _fileobj_to_fd(fileobj)
  File "/home/mauro/.pyenv/versions/3.10.7/lib/python3.10/selectors.py", line 42, in _fileobj_to_fd
    raise ValueError("Invalid file descriptor: {}".format(fd))

This only happens under PyVISA-py 0.8.0. Prior versions work fine.

To Reproduce

Steps to reproduce the behavior:

1. Run the following code snippet:

   import pyvisa
   
   rm = pyvisa.ResourceManager("@py")
   rm.list_resources()
   rm.close()

Output of pyvisa-info

Machine Details:
   Platform ID:    Linux-6.8.0-60-generic-x86_64-with-glibc2.39
   Processor:      x86_64

Python:
   Implementation: CPython
   Executable:     /home/mauro/.pyenv/versions/3.10.7/envs/instruments/bin/python3.10
   Version:        3.10.7
   Compiler:       GCC 8.5.0
   Architecture:   ('x86', 64)
   Build:          Nov  7 2022 15:27:13 (#main)
   Unicode:        UCS4

PyVISA Version: 1.15.0

Backends:
   ivi:
      Version: 1.15.0 (bundled with PyVISA)
      #1: /usr/lib/x86_64-linux-gnu/libvisa.so.25.3.0:
         found by: auto
         architecture:
            ('x86', 64)
         Vendor: National Instruments
         Impl. Version: 26215168
         Spec. Version: 7340032
   py:
      Version: 0.8.0
      TCPIP INSTR: Available 
         Resource discovery:
         - VXI-11: ok
         - hislip: ok
      TCPIP SOCKET: Available 
      PRLGX_TCPIP INTFC: Available 
      GPIB INSTR: Available 
      ASRL INSTR:
         Please install PySerial (>=3.0) to use this resource type.
         No module named 'serial'
      USB INSTR:
         Please install PyUSB to use this resource type.
         No module named 'usb'
      USB RAW:
         Please install PyUSB to use this resource type.
         No module named 'usb'
      VICP INSTR:
         Please install PyVICP to use this resource type.
      PRLGX_ASRL INTFC:
         Please install PySerial (>=3.0) to use this resource type.
         No module named 'serial'
      GPIB INTFC:
         Please install linux-gpib (Linux) or gpib-ctypes (Windows, Linux) to use this resource type. Note that installing gpib-ctypes will give you access to a broader range of functionalities.
         No module named 'gpib'

[MatthieuDartiailh]

It is likely related to resource discovery over ethernet. I will try to have a look. Thanks for reporting.