Improve error message for missing attribute (#20779)
Summary:
Fixes #20495 .
Now for
```python
class A(torch.jit.ScriptModule):
def __init__(self):
super(A, self).__init__()
torch.jit.script_method
def forward(self, x):
return x + self.whatisgoingon
class B(A):
def __init__(self):
super(B, self).__init__()
torch.jit.script_method
def bar(self, x):
return x * x
A()
```
it does
```
RuntimeError:
attribute 'whatisgoingon' does not exist:
torch.jit.script_method
def forward(self, x):
return x + self.whatisgoingon
~~~~~~~~~~~~~~~~~~ <--- HERE
```
I added a test in `test_jit.py` as well.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/20779
Differential Revision: D15441138
Pulled By: Chillee
fbshipit-source-id: 88f458c36b5e32a1ffc467b27bbc28a3c5c07321
