visualstudio_py_testlauncher.py - format_exception() missing 3 required positional arguments: 'etype', 'value', and 'tb'

[Ark-kun]

I got an exception while trying to debug a unittest. The exception was from a bug in VSCode Python extension itself:

Exception has occurred: TypeError
format_exception() missing 3 required positional arguments: 'etype', 'value', and 'tb'
  File "C:\Users\Ark\.vscode\extensions\ms-python.python-2018.9.2\pythonFiles\PythonTools\visualstudio_py_testlauncher.py", line 344, in main
    pass
  File "C:\Users\Ark\.vscode\extensions\ms-python.python-2018.9.2\pythonFiles\PythonTools\visualstudio_py_testlauncher.py", line 347, in <module>
    main()

I looked at the extension's code and the error is correct. See https://github.com/DonJayamanne/pythonVSCode/commit/3e50a6821dc5db60cc87b4205fdb7c712d7fd7fb#r31258938

Environment data

• VS Code version: 1.28.2
• Extension version: 2018-10-01
• OS and version: Windows 10
• Python version: 3.7.0 x64
• Type of virtual environment used: N/A

Actual behavior

Exception has occurred: TypeError
format_exception() missing 3 required positional arguments: 'etype', 'value', and 'tb'
  File "C:\Users\Ark\.vscode\extensions\ms-python.python-2018.9.2\pythonFiles\PythonTools\visualstudio_py_testlauncher.py", line 344, in main
    pass
  File "C:\Users\Ark\.vscode\extensions\ms-python.python-2018.9.2\pythonFiles\PythonTools\visualstudio_py_testlauncher.py", line 347, in <module>
    main()

Expected behavior

No exception

[VCPintoHUUB]

Hi, Any workaround for this bug? Will it be fixed?

[VCPintoHUUB]

Hi, Any hope on seeing this fixed?

[brettcannon]

We are going through old issues and we noticed that no one had replied to this issue. I want to apologize for the oversight and to let you know that the issue was triaged (as shown by the labels applied to this issue).

[eleanorjboyd]

Hello! I have reviewed this issue and given the architectural changes of the testing rewrite, this issue should no longer exist on the rewrite. Therefore I am going to close this issue but please comment or open a new issue if you are still seeing a problem when you try this yourself!

To use the rewrite yourself just add ”python.experiments.optInto": ["pythonTestAdapter"] to your user settings. You can confirm you have the rewrite enabled by setting your log level to trace, via the Developer: Set Log Level command in the command palette. Then check to see if Experiment 'pythonTestAdapter' is active is in your python logs.

Thanks!