Output for ExceptionGroups hides sub-exceptions

[ugtar]

Only the outer-most exception seems be be visible in the output for a handled ExceptionGroup. here is a contrived example:

>>> def fn():
...     e = ExceptionGroup("multiple exceptions",
...             [ExceptionGroup("file not found",
...                 [FileNotFoundError("unknown filename file1.txt"), 
...                  FileNotFoundError("unknown filename file2.txt")]), 
...              KeyError("missing key")])
...     raise e

the normal output shows the sub-exceptions:

>>> fn()
  + Exception Group Traceback (most recent call last):
  |   File "<stdin>", line 1, in <module>
  |   File "<stdin>", line 7, in fn
  | ExceptionGroup: multiple exceptions (2 sub-exceptions)
  +-+---------------- 1 ----------------
    | ExceptionGroup: file not found (2 sub-exceptions)
    +-+---------------- 1 ----------------
      | FileNotFoundError: unknown filename file1.txt
      +---------------- 2 ----------------
      | FileNotFoundError: unknown filename file2.txt
      +------------------------------------
    +---------------- 2 ----------------
    | KeyError: 'missing key'
    +------------------------------------

but with stackprinter

>>> import stackprinter
>>> stackprinter.set_excepthook()
>>> fn()
File "<stdin>", line 1, in <module>

File "<stdin>", line 7, in fn

ExceptionGroup: multiple exceptions (2 sub-exceptions)

all we see is there are sub-exceptions.

I don't have any great suggestions, but maybe at least stackprinter could fall back to the basic output in the case of an ExceptionGroup

[cknd]

Ah dang. Agreed, it should at least fall back to default output, if not fully supporting exception groups

[ugtar]

I thought to work around this by setting add_summary=True always, but it looks like the summary traceback is not the builtin traceback format, but a similar one, and in the case of ExceptionGroups it's still no good

>>> fn()
File "<stdin>", line 1, in <module>

File "<stdin>", line 7, in fn

---- (full traceback above) ----
File "<stdin>", line 1, in <module>
File "<stdin>", line 7, in fn

ExceptionGroup: multiple exceptions (2 sub-exceptions)

:man_shrugging:

maybe the summary could be made to use the default formatter?

[ugtar]

Also, fwiw, falling back to the native exception formatter is what ipython is currently doing for exception groups https://github.com/ipython/ipython/pull/14108/

[cknd]

Fixed in the latest 0.2.11 on pypi! Thanks for the report