[testing] improve broadcasts_input error message (#58295)
Summary:
Context:
The Error message when `broadcasts_input` is marked incorrectly is uninformative [See Error Currently]
https://github.com/pytorch/pytorch/pull/57941#discussion_r631749435
Error Currently
```
Traceback (most recent call last):
File "/home/kshiteej/Pytorch/pytorch_i0_promotion/test/test_ops.py", line 326, in test_variant_consistency_eager
_test_consistency_helper(samples, variants)
File "/home/kshiteej/Pytorch/pytorch_i0_promotion/test/test_ops.py", line 310, in _test_consistency_helper
variant_forward = variant(cloned,
File "/home/kshiteej/.conda/envs/pytorch-cuda-dev/lib/python3.8/unittest/case.py", line 227, in __exit__
self._raiseFailure("{} not raised".format(exc_name))
File "/home/kshiteej/.conda/envs/pytorch-cuda-dev/lib/python3.8/unittest/case.py", line 164, in _raiseFailure
raise self.test_case.failureException(msg)
AssertionError: RuntimeError not raised
```
Error After PR
```
Traceback (most recent call last):
File "/home/kshiteej/Pytorch/pytorch_i0_promotion/test/test_ops.py", line 329, in test_variant_consistency_eager
_test_consistency_helper(samples, variants)
File "/home/kshiteej/Pytorch/pytorch_i0_promotion/test/test_ops.py", line 313, in _test_consistency_helper
variant_forward = variant(cloned,
File "/home/kshiteej/.conda/envs/pytorch-cuda-dev/lib/python3.8/unittest/case.py", line 227, in __exit__
self._raiseFailure("{} not raised".format(exc_name))
File "/home/kshiteej/.conda/envs/pytorch-cuda-dev/lib/python3.8/unittest/case.py", line 164, in _raiseFailure
raise self.test_case.failureException(msg)
AssertionError: RuntimeError not raised : inplace variant either allowed resizing or you have marked the sample SampleInput(input=Tensor, args=(tensor([[[ 2.1750, -8.5027, -3.1403, -6.9942, 3.2609],
[-2.5057, -5.9123, -5.4633, 6.1203, -8.2124],
[-3.5802, -8.4869, -6.0700, 2.3431, -8.1955],
[-7.3316, 1.3248, -6.8661, 7.1483, -8.0719],
[ 4.5977, -4.0448, -6.2044, -2.1314, -8.4956]],
[[ 3.2769, -8.4360, 1.2826, 7.1749, 4.7653],
[-0.2816, -2.5997, -4.7659, -3.7814, 3.9704],
[-2.1778, -3.8117, -6.0276, -0.8423, -5.9646],
[ 8.6544, -3.0922, 0.2558, -4.9318, -4.7596],
[ 4.5583, 4.3830, 5.8793, 0.9713, -2.1481]],
[[-1.0447, 0.9334, 7.6405, -4.8933, -7.4010],
[ 7.7168, -8.4266, -5.5980, -6.9368, 7.1309],
[-8.7720, -5.0890, -0.4975, 1.9518, 1.7074],
[-8.5783, 8.5510, -8.5459, -3.5451, 8.4319],
[ 8.5052, -8.9149, -6.6298, -1.2750, -5.7367]],
[[-6.5625, 8.2795, -4.9311, 1.9501, -7.1777],
[-8.4035, 1.1136, -7.6418, -7.0726, -2.8281],
[ 4.2668, -0.2883, -6.2246, 2.3396, 1.2911],
[ 4.6550, -1.9525, 4.4873, -3.8061, -0.8653],
[-3.4256, 4.4423, 8.2937, -5.3456, -4.2624]],
[[ 7.6128, -6.3932, 4.7131, -5.4938, 6.4792],
[-6.5385, 2.4385, 4.5570, 3.7803, -8.3281],
[-2.9785, -4.4745, -1.1778, -8.9324, 1.3663],
[ 3.7437, 3.5171, -6.3135, -8.4519, -2.7033],
[-5.0568, -8.4630, -4.2870, -3.7284, -1.5238]]], device='cuda:0',
dtype=torch.float32, requires_grad=True),), broadcasts_input=True) incorrectly with `broadcasts_self=True
```
**NOTE**:
Printing the sample looks very verbose and it may be hard to figure out which sample is incorrectly configured if there are multiple samples with similar input shapes.
Two Options to make this error less verbose
* Don't print the sample and just print `inplace variant either allowed resizing or you have marked one of the sample incorrectly with broadcasts_self=True`
* Have some mechanism to name samples which will be printed in the `repr` (which will need extra machinery)
Pull Request resolved: https://github.com/pytorch/pytorch/pull/58295
Reviewed By: ngimel
Differential Revision: D28627308
Pulled By: mruberry
fbshipit-source-id: b3bdeacac3cf9c0d984f0b85410ecce474291d20
