title: Importing pytorch geometric results in an error message
body: <p>I'm suddenly unable to import pytorch geometric and I cannot figure out why. I've added a screenshot of the packages in my conda environment and the error message that I get when I try to <code>import torch_geometric</code>.</p>
  <pre class="lang-py prettyprint-override"><code>import torch
  import torch.nn.functional as F
  from torch_geometric.nn import GCNConv
  </code></pre>
  <p>Error message:</p>
  <blockquote>
  <p>OSError: dlopen(/Users/anstercharles/opt/anaconda3/lib/python3.8/site-packages/torch_sparse/_convert_cpu.so, 6): Symbol not found: __ZN2at8internal13_parallel_runExxxRKNSt3__18functionIFvxxmEEE
  Referenced from: /Users/anstercharles/opt/anaconda3/lib/python3.8/site-packages/torch_sparse/_convert_cpu.so
  Expected in: /Users/anstercharles/opt/anaconda3/lib/python3.8/site-packages/torch/lib/libtorch_cpu.dylib
  in /Users/anstercharles/opt/anaconda3/lib/python3.8/site-packages/torch_sparse/_convert_cpu.so</p>
  </blockquote>
  <p>Running:</p>
  <pre><code>conda list pytorch
  </code></pre>
  <p>Gives me:</p>
  <div class="s-table-container">
  <table class="s-table">
  <thead>
  <tr>
  <th>Name</th>
  <th>Version</th>
  <th>Build</th>
  <th>Channel</th>
  </tr>
  </thead>
  <tbody>
  <tr>
  <td>pytorch</td>
  <td>1.9.0</td>
  <td>cpu_py38h490fcb8_1</td>
  <td>conda-forge</td>
  </tr>
  <tr>
  <td>pytorch-cluster</td>
  <td>1.5.9</td>
  <td>py38_torch_1.9.0_cpu</td>
  <td>rusty1s</td>
  </tr>
  <tr>
  <td>pytorch-geometric</td>
  <td>1.7.2</td>
  <td>py38_torch_1.9.0_cpu</td>
  <td>rusty1s</td>
  </tr>
  <tr>
  <td>pytorch-scatter</td>
  <td>2.0.8</td>
  <td>py38_torch_1.9.0_cpu</td>
  <td>rusty1s</td>
  </tr>
  <tr>
  <td>pytorch-sparse</td>
  <td>0.6.11</td>
  <td>py38_torch_1.9.0_cpu</td>
  <td>rusty1s</td>
  </tr>
  <tr>
  <td>pytorch-spline-conv</td>
  <td>1.2.1</td>
  <td>py38_torch_1.9.0_cpu</td>
  <td>rusty1s</td>
  </tr>
  </tbody>
  </table>
  </div>
  <p><a href="https://i.stack.imgur.com/sk39S.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/sk39S.png" alt="I have the packages installed and I was using them just a few minutes ago." /></a></p>
  <hr />
  <h2>Additional Details</h2>
  <ul>
  <li>OS: MacOS Mojave</li>
  <li>Anaconda 3</li>
  <li>Python 3.8</li>
  </ul>