raise Exception from self leads to reported error

[audoh-tickitto]

Environment data

• Language Server version: 2020.12.2
• OS and version: Windows 10 Pro, 20H2, 19042.685
• Python version (& distribution if applicable, e.g. Anaconda): 3.9.0 acquired via pyenv

Expected behaviour

No error should be reported.

Actual behaviour

The following error is reported:

Expected exception object or None
  "FooError" does not derive from BaseException

Logs

N/A

Code Snippet / Additional information

class FooError(BaseException):
    def bar(self) -> None:
        raise Exception("baz") from self

The same also happens if extending any subclass of BaseException.

[judej]

@erictraut, would you please take a look a this?
thanks

[erictraut]

Thanks for the bug report. This will be fixed in the next release.

[jakebailey]

This issue has been fixed in version 2021.1.0, which we've just released. You can find the changelog here: https://github.com/microsoft/pylance-release/blob/main/CHANGELOG.md#202110-6-january-2021