title: PyTorch XLA incompatibility issue when running a modified official example
body: <p>When running <a href="https://colab.research.google.com/gist/rwbfd/dd7fbea39ffcfa5ca18117045d694517/pytorch-tpu.ipynb#scrollTo=pTmxZL5ymp8P" rel="nofollow noreferrer">this sample using PyTorch XLA</a> modified slightly from the official sample in Colab, the following errors are presented:</p>
  <p><code>ImportError: /usr/local/lib/python3.7/dist-packages/_XLAC.cpython-37m-x86_64-linux-gnu.so: undefined symbol: _ZN2at13_foreach_erf_EN3c108ArrayRefINS_6TensorEEE</code>.</p>
  <p>This seems to be from the code snippet <code>import torch_xla</code>, which seems to point to an incompatibility error. However, I am not able to locate the error.</p>