[misc] add hint for AttributeError

[youkaichao]

try to fix #5456

[mgoin]

@youkaichao I like the error message, however needing to manually add a decorator for each function seems messy.

Could you possibly try this method of attaching the decorator to all functions in the _custom_ops module? I haven't tested this, but it should be something like this

def hint_on_error(fn):

    def wrapper(*args, **kwargs):
        try:
            return fn(*args, **kwargs)
        except AttributeError as e:
            msg = (
                "Error in calling custom op %s: %s\n"
                "Possibly you have built or installed an obsolete version of vllm.\n"
                "Please try a clean build and install of vllm,"
                "or remove old built files such as vllm/*.so and build/ .")
            logger.error(msg, fn.__name__, e)
            raise e

    return wrapper

import sys
import inspect

# Get the current module
current_module = sys.modules[__name__]

# Iterate through all functions in the current module
for name, obj in inspect.getmembers(current_module, inspect.isfunction):
    # Apply the decorator to each function
    setattr(current_module, name, hint_on_error(obj))

[youkaichao]

@mgoin I updated the code with auto-decoration. here is the example message I get:

ERROR 06-12 12:21:06 _custom_ops.py:41] Error in calling custom op reshape_and_cache: '_OpNamespace' '_C_cache_ops' object has no attribute 'reshape_and_cache'
ERROR 06-12 12:21:06 _custom_ops.py:41] Possibly you have built or installed an obsolete version of vllm.
ERROR 06-12 12:21:06 _custom_ops.py:41] Please try a clean build and install of vllm,or remove old built files such as vllm/*.so and build/ .
[rank0]: Traceback (most recent call last):

I think this should be clear enough.

[mgoin]

Nice job, I like your approach as a shim