title: UnsatisfiableError glibc and cudatoolkit
body: <pre><code>conda install  -c anaconda -c conda-forge -c nvidia cudatoolkit=11 tensorflow-gpu=2
  </code></pre>
  <p>I want to install cudatoolkit=11 and tensorflow-gpu=2, but conda gave me the following error message</p>
  <pre><code>UnsatisfiableError: The following specifications were found to be incompatible with your system:
  
    - feature:/linux-64::__glibc==2.31=0
    - cudatoolkit=11 -&gt; __glibc[version='&gt;=2.17,&lt;3.0.a0']
  
  Your installed version is: 2.31
  </code></pre>
  <p>If I run</p>
  <pre><code>conda install  -c anaconda -c conda-forge -c nvidia cudatoolkit=11
  </code></pre>
  <p>conda can successfully install cudatoolkit=11.</p>
  <p>Since glibc is a system feature, why installing cudatoolkit by itself is ok?</p>
  <p>Why isn't glic 2.31 in range &gt;=2.17,&lt;3.0.a0?</p>