title: How does anaconda pick cudatoolkit
body: <p>I have multiple enviroments of anaconda with different cuda toolkits installed on them.</p>
  
  <p>env1 has  <code>cudatoolkit               10.0.130</code> </p>
  
  <p>env2 has  <code>cudatoolkit               10.1.168</code></p>
  
  <p>env3 has   <code>cudatoolkit               10.2.89</code> </p>
  
  <p>I found these by running <code>conda list</code> on each environment.</p>
  
  <p>When i do <code>nvidia-smi</code> i get the following output no matter which environment i am in</p>
  
  <pre><code>+-----------------------------------------------------------------------------+
  | NVIDIA-SMI 435.21       Driver Version: 435.21       CUDA Version: 10.1     |
  |-------------------------------+----------------------+----------------------+
  | GPU  Name        Persistence-M| Bus-Id        Disp.A | Volatile Uncorr. ECC |
  | Fan  Temp  Perf  Pwr:Usage/Cap|         Memory-Usage | GPU-Util  Compute M. |
  |===============================+======================+======================|
  |   0  GeForce RTX 208...  Off  | 00000000:01:00.0  On |                  N/A |
  |  0%   42C    P8     7W / 260W |    640MiB / 11016MiB |      2%      Default |
  +-------------------------------+----------------------+----------------------+
  </code></pre>
  
  <p>Is the cuda version shown above is same as cuda toolkit version? 
  If so why is it same in all the enviroments?</p>
  
  <p>In env3 which has <code>cudatoolkit version 10.2.89</code>, i tried installing <a href="https://docs-cupy.chainer.org/en/stable/index.html" rel="nofollow noreferrer">cupy</a> library using the command <code>pip install cupy-cuda102</code> .
  I get the following error when i try to do it.</p>
  
  <pre><code>ERROR: Could not find a version that satisfies the requirement cupy-cuda102 (from versions: none)
  ERROR: No matching distribution found for cupy-cuda102
  </code></pre>
  
  <p>I was able to install using <code>pip install cupy-cuda101</code> which is for cuda 10.1.
  Why is it not able to find cudatoolkit 10.2?</p>
  
  <p>The reason i am asking this question is because, i am getting an error <code>cupy.cuda.cublas.CUBLASError: CUBLAS_STATUS_NOT_INITIALIZED</code> when i am running a deep learning model. I am just wondering if cudatoolkit version has something to do with this error.Even if this error is not related to cudatoolkit version i want to know how anaconda uses cudatoolkit.</p>