pvpython incompatible with argparse

I am writing a python script which uses the argparse module and some paraview.simple functions and I am facing an odd problem.
When the script has to exit due to lack of arguments for the parser, the terminal freezes.
I have checked the script with python under Paraview versions 5.5 to 5.8. It works fine for Paraview 5.5 and 5.6 and does not work for the newer versions.
I have made a simple example to reproduce this problem:

Steps to reproduce

  • Save the following code in a python file “test.py”:
#!/usr/bin/env python

from paraview.simple import *
import argparse

if __name__ == "__main__":

    # parse command line argument
    parser = argparse.ArgumentParser(prog='PROG',description='Test')
    parser.add_argument("-f",metavar="File",required=True, type=str)
    args = vars(parser.parse_args())

  • Run:
pvpython test.py -h

Expected Output
The following text should be printed and the code exit.

usage: PROG [-h] -f File


optional arguments:
  -h, --help  show this help message and exit
  -f File

Observed behavior

After printing the usage message the code does not exit and pressing Ctrl+C will result in the following:

VisRTX 0.1.6, using devices:
 0: GeForce GTX 1660 Ti (Total: 6.2 GB, Available: 5.4 GB)
usage: PROG [-h] -f File


optional arguments:
  -h, --help  show this help message and exit
  -f File

Loguru caught a signal: SIGINT
malloc(): unsorted double linked list corrupted

Loguru caught a signal: SIGABRT

My operating system is Centos 8 and my only option here is to close the terminal (Ctrl+q).

Possible cause

This problem does not occur if the following line in the code is commented:

from paraview.simple import *

so importing paraview.simple breaks the code.

You’re most likely seeing the same issue as here.

ParaView 5.9 has updates to the OSPray libraries which should address this finalization issue.

You may overcome the problem in your script by deferring the from paraview.simple import * until after the argument parsing has happened.

Thank you for your response.
I will apply this workaround and wait for Paraview 5.9 then. :slight_smile: