Fix dynamo stack trace

[yushangdi]

Fixes #165911

• Add message to Attribute error so we see Developer debug context: raised exception AttributeError(["'Linear' object has no attribute 'w'"]) instead of just Developer debug context: raised exception AttributeError([])
• Add stack trace in ObservedException so we display the inner most error stack trace back to user code

Output:

/data/users/shangdiy/pytorch/torch/__init__.py:2641: UserWarning: You are calling torch.compile inside torch.export region. To capture an useful graph, we will implicitly switch to torch.compile(backend=eager)
  warnings.warn(
Traceback (most recent call last):
  File "/data/users/shangdiy/pytorch/torch/_dynamo/variables/user_defined.py", line 1385, in var_getattr
    subobj = self._getattr_static(name)
             ^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/data/users/shangdiy/pytorch/torch/_dynamo/variables/user_defined.py", line 1256, in _getattr_static
    subobj = type(self.value).__getattribute__(self.value, name)
             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
AttributeError: 'Linear' object has no attribute 'w'

During handling of the above exception, another exception occurred:

torch._dynamo.exc.ObservedAttributeError: 'Linear' object has no attribute 'w'

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
  File "/data/users/shangdiy/pytorch/test.py", line 34, in <module>
    mod = torch._dynamo.functional_export._dynamo_graph_capture_for_export(Model())(x)
          ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/data/users/shangdiy/pytorch/torch/_dynamo/functional_export.py", line 481, in inner
    out = fullgraph_capture(
          ^^^^^^^^^^^^^^^^^^
  File "/data/users/shangdiy/pytorch/torch/_dynamo/convert_frame.py", line 1053, in fullgraph_capture
    return _fullgraph_capture_frame(
           ^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/data/users/shangdiy/pytorch/torch/_dynamo/convert_frame.py", line 1115, in _fullgraph_capture_frame
    raise e.with_traceback(None) from e.__cause__  # User compiler error
    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
torch._dynamo.exc.Unsupported: Observed exception
  Explanation: Dynamo found no exception handler at the top-level compiled function when encountering an exception. Exception will propagate outside the compiled region.
  Hint: Dynamo has detected that tracing the code will result in an error when running in eager. Please double check that your code doesn't contain a similar error when actually running eager/uncompiled.
  Hint: It may be possible to write Dynamo tracing rules for this code. Please report an issue to PyTorch if you encounter this graph break often and it is causing performance issues.

  Developer debug context: raised exception AttributeError(["'Linear' object has no attribute 'w'"])

 For more details about this graph break, please visit: https://meta-pytorch.github.io/compile-graph-break-site/gb/gb0088.html

from user code:
   File "/data/users/shangdiy/pytorch/torch/_dynamo/functional_export.py", line 171, in forward
    res = self._export_root(*args, **kwargs)
  File "/data/users/shangdiy/pytorch/test.py", line 31, in forward
    weight = self.linear.w

Set TORCHDYNAMO_VERBOSE=1 for the internal stack trace (please do this especially if you're reporting a bug to PyTorch). For even more developer context, set TORCH_LOGS="+dynamo"

cc @voznesenskym @penguinwu @EikanWang @jgong5 @Guobing-Chen @XiaobingSuper @zhuhaozhe @blzheng @wenzhe-nrv @jiayisunx @chenyang78 @kadeng @chauhang @amjames @Lucaskabela @mlazos

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✅ You can merge normally! (1 Unrelated Failure)

As of commit e192036 with merge base 8cb2fb4 ():

FLAKY - The following job failed but was likely due to flakiness present on trunk:

• trunk / linux-jammy-py3-clang12-executorch / test (executorch, 1, 1, linux.2xlarge) (gh) (similar failure)
  export/tests/test_target_recipes.py::TestTargetRecipes::test_w2l_model

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[Lucaskabela]

Flagged a few more places we might be able to bubble up the exception here

[yushangdi]

@pytorchbot merge

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