`dill.load_session()` raises `NameError: name 'UnpicklingError' is not defined` about dill HOT 5 CLOSED

I've created a simple PR to fix this: #649

With this PR, the above code will print <class '_pickle.UnpicklingError'> unable to identify main module instead. I suppose this behavior makes more sense.

@mmckerns Could you please review it?

from dill.

thanks

from dill.

Hm, ok. Can you provide a minimal session that produces this error? Doing so would help us reproduce, confirm, and fix the issue.

from dill.

I've updated my description above. Sorry for any confusion. The file I was loading is NOT a valid dump file.

from dill.

Minimum repro:

import tempfile

import dill

with tempfile.TemporaryFile() as f:
    f.write("some content that is not a valid dump".encode())
    f.flush()
    try:
        dill.load_session(f.name)
    except Exception as e:
        print(type(e), str(e))

This will print: <class 'NameError'> name 'UnpicklingError' is not defined

from dill.