Bug located in test_siwave_create_circuit_port_on_net

### Before submitting the issue

- [x] I have searched among the existing issues
- [x] I am using a Python virtual environment

### Description of the bug

This test fails randomly on Linux
tests/system/test_edb.py::TestClass::test_siwave_create_circuit_port_on_net Fatal Python error: Aborted

### Steps To Reproduce

run unittest

### Which Operating System are you using?

Windows

### Which Python version are you using?

3.7

### Installed packages

all

Start with tests/system/test_edb.py::TestClass::test_siwave_create_circuit_port_on_net and run the unittest to reproduce the intermittent abort. Compare the reported Linux failure with the stated Windows and Python 3.7 environment; done means identifying and resolving the cause so the test runs reliably.

Written by the indexing model from the issue text.