<h2 dir="auto">🐛 Bug</h2>

<h2 dir="auto">To Reproduce</h2>
<p dir="auto">Steps to reproduce the behavior:</p>
<ol dir="auto">
<li>Execute <code class="notranslate">conda install pytorch torchvision cudatoolkit=10.0 -c pytorch</code> to intall pytorch1.1 and torchvision0.3.0</li>
<li>Execute <code class="notranslate">conda install pytorch-nightly -c pytorch</code> to install pytorch1.2</li>
<li>Import torchvision then get the following error.</li>
</ol>
<div class="snippet-clipboard-content notranslate position-relative overflow-auto" data-snippet-clipboard-copy-content="Traceback (most recent call last):
  File &quot;&lt;stdin&gt;&quot;, line 1, in &lt;module&gt;
  File &quot;/opt/anaconda/lib/python3.7/site-packages/torchvision/__init__.py&quot;, line 1, in &lt;module&gt;
    from torchvision import models
  File &quot;/opt/anaconda/lib/python3.7/site-packages/torchvision/models/__init__.py&quot;, line 11, in &lt;module&gt;
    from . import detection
  File &quot;/opt/anaconda/lib/python3.7/site-packages/torchvision/models/detection/__init__.py&quot;, line 1, in &lt;module&gt;
    from .faster_rcnn import *
  File &quot;/opt/anaconda/lib/python3.7/site-packages/torchvision/models/detection/faster_rcnn.py&quot;, line 7, in &lt;module&gt;
    from torchvision.ops import misc as misc_nn_ops
  File &quot;/opt/anaconda/lib/python3.7/site-packages/torchvision/ops/__init__.py&quot;, line 1, in &lt;module&gt;
    from .boxes import nms, box_iou
  File &quot;/opt/anaconda/lib/python3.7/site-packages/torchvision/ops/boxes.py&quot;, line 2, in &lt;module&gt;
    from torchvision import _C
ImportError: /opt/anaconda/lib/python3.7/site-packages/torchvision/_C.cpython-37m-x86_64-linux-gnu.so: undefined symbol: _ZN2at7getTypeERKNS_6TensorE"><pre class="notranslate"><code class="notranslate">Traceback (most recent call last):
  File "&lt;stdin&gt;", line 1, in &lt;module&gt;
  File "/opt/anaconda/lib/python3.7/site-packages/torchvision/__init__.py", line 1, in &lt;module&gt;
    from torchvision import models
  File "/opt/anaconda/lib/python3.7/site-packages/torchvision/models/__init__.py", line 11, in &lt;module&gt;
    from . import detection
  File "/opt/anaconda/lib/python3.7/site-packages/torchvision/models/detection/__init__.py", line 1, in &lt;module&gt;
    from .faster_rcnn import *
  File "/opt/anaconda/lib/python3.7/site-packages/torchvision/models/detection/faster_rcnn.py", line 7, in &lt;module&gt;
    from torchvision.ops import misc as misc_nn_ops
  File "/opt/anaconda/lib/python3.7/site-packages/torchvision/ops/__init__.py", line 1, in &lt;module&gt;
    from .boxes import nms, box_iou
  File "/opt/anaconda/lib/python3.7/site-packages/torchvision/ops/boxes.py", line 2, in &lt;module&gt;
    from torchvision import _C
ImportError: /opt/anaconda/lib/python3.7/site-packages/torchvision/_C.cpython-37m-x86_64-linux-gnu.so: undefined symbol: _ZN2at7getTypeERKNS_6TensorE
</code></pre></div>


<h2 dir="auto">Environment</h2>
<p dir="auto">Versions of relevant libraries:<br>
[pip] numpy==1.16.2<br>
[pip] numpydoc==0.8.0<br>
[pip] torch==1.2.0.dev20190730+cu100<br>
[pip] torchvision==0.3.0<br>
[conda] blas                      1.0                         mkl<br>
[conda] mkl                       2019.3                      199<br>
[conda] mkl-service               1.1.2            py37he904b0f_5<br>
[conda] mkl_fft                   1.0.10           py37ha843d7b_0<br>
[conda] mkl_random                1.0.2            py37hd81dba3_0<br>
[conda] pytorch                   1.1.0           py3.7_cuda10.0.130_cudnn7.5.1_0<br>
[conda] pytorch-nightly           1.2.0.dev20190730+cu100 py3.7_cuda10.0.130_cudnn7.6.1_0    pytorch<br>
[conda] torchvision               0.3.0           py37_cu10.0.130_1</p>
<h2 dir="auto">Additional context</h2>

<p dir="auto">This import error only happens with pytorch1.2 and torchvision0.3, while pytorch1.2 and torchvision0.2 are ok. So there may be some incompatible problem between torchvision0.3 and pytorch1.2.</p>
<p dir="auto">The official website does not provide the torchvison version installation method.<br>
Here is the error message  when torchvison 0.3.0 is used.<br>
torchvision/_C.cpython-36m-x86_64-linux-gnu.so: undefined symbol: _ZN2at7getTypeERKNS_6TensorE</p>
<p dir="auto">That should be caused by the mismatch version  between pytorch-nightly and torchvision  0.3.0.</p>