python311-exceptiongroup

This is a backport of the ``BaseExceptionGroup`` and ``ExceptionGroup`` classes from Python 3.11. It contains the following: * The ``exceptiongroup.BaseExceptionGroup`` and ``exceptiongroup.ExceptionGroup`` classes * A utility function (``exceptiongroup.catch()``) for catching exceptions possibly nested in an exception group * Patches to the ``TracebackException`` class that properly formats exception groups (installed on import) * An exception hook that handles formatting of exception groups through ``TracebackException`` (installed on import) * Special versions of some of the functions from the ``traceback`` module, modified to correctly handle exception groups even when monkey patching is disabled, or blocked by another custom exception hook: * ``traceback.format_exception()`` * ``traceback.format_exception_only()`` * ``traceback.print_exception()`` * ``traceback.print_exc()`` If this package is imported on Python 3.11 or later, the built-in implementations of the exception group classes are used instead, ``TracebackException`` is not monkey patched and the exception hook won't be installed.