title: Could not find a version that satisfies the requirement tensorflow==1.15 (from versions: none). No matching distribution found
body: <p>I created a virtual environment in Pycharm for Python 3.7
  But when I try to install a lower version of Tensorflow in that venv, using </p>
  
  <pre><code>pip install tensorflow==1.15
  </code></pre>
  
  <p>I get this error. </p>
  
  <pre><code>ERROR: Could not find a version that satisfies the requirement tensorflow==1.15 (from versions: none)
  ERROR: No matching distribution found for tensorflow==1.15
  </code></pre>
  
  <p>My pip is upgraded. 
  MY OS is Arch  Linux. </p>
  
  <p>Any suggestions?</p>