Instantiation exception also raises an exception sometimes

[bryant1410]

🐛 Bug

Description

When there's an instantiation exception, raising a chained exception sometimes also fails because it doesn't take an argument:

hydra/hydra/_internal/instantiate/_instantiate2.py

Lines 63 to 66 in 9759f87

	except Exception as e:
	raise type(e)(
	f"Error instantiating '{_convert_target_to_string(_target_)}' : {e}"
	).with_traceback(sys.exc_info()[2])

Checklist

• I checked on the latest version of Hydra
• I created a minimal repro (See this for tips).

To reproduce

Try to instantiate an object such that it raises an exception that doesn't take any argument.

Expected Behavior

Maybe it should try to show another type of exception instead? Or chaining (from e).

System information

• Hydra Version : 1.1
• Python version : 3.8
• Virtual environment type and version : conda 4.11
• Operating system : Ubuntu 18.04

Additional context

Add any other context about the problem here.

[Jasha10]

Hi @bryant1410, thanks for reporting this.

Here is a minimal repro:

# module.py
class MyException(Exception):
    def __init__(self):
        """Init method taking no argument"""
        pass

def foo():
    raise MyException()

# run.py
from hydra.utils import instantiate

instantiate({"_target_": "module.foo"})

$ python run.py
Traceback (most recent call last):
  File "/Users/jasha10/hydra.git/hydra/_internal/instantiate/_instantiate2.py", line 62, in _call_target
    return _target_(*args, **kwargs)
  File "/Users/jasha10/hydra_tmp/1911/module.py", line 8, in foo
    raise MyException()
module.MyException

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/Users/jasha10/hydra_tmp/1911/run.py", line 4, in <module>
    instantiate({"_target_": "module.foo"})
  File "/Users/jasha10/hydra.git/hydra/_internal/instantiate/_instantiate2.py", line 180, in instantiate
    return instantiate_node(config, *args, recursive=_recursive_, convert=_convert_)
  File "/Users/jasha10/hydra.git/hydra/_internal/instantiate/_instantiate2.py", line 249, in instantiate_node
    return _call_target(_target_, *args, **kwargs)
  File "/Users/jasha10/hydra.git/hydra/_internal/instantiate/_instantiate2.py", line 64, in _call_target
    raise type(e)(
TypeError: __init__() takes 1 positional argument but 2 were given

[Jasha10]

I like your proposed idea of exception chaining.