title: pip can't find tensorflow-gpu 2.0-alpha
body: <p>I'm trying to install tensorflow-gpu where the version is 2.0.0-alpha0. I've tried these two specific commands:</p>
  
  <pre><code>pip install tensorflow-gpu==2.0.0-alpha0
  pip install -U --pre tensorflow-gpu==2.0.0-alpha0
  </code></pre>
  
  <p>pip says:</p>
  
  <pre><code>Collecting tensorflow-gpu==2.0.0-alpha0
  Could not find a version that satisfies the requirement tensorflow-gpu==2.0.0-alpha0 (from versions: )
  No matching distribution found for tensorflow-gpu==2.0.0-alpha0
  </code></pre>
  
  <p>However the tensorflow-gpu page on <a href="https://pypi.org/project/tensorflow-gpu/#history" rel="nofollow noreferrer">pypi</a> definitely has version 2.0.0-alpha0. I know I can build from source or download the package directly from pypi, but I'd prefer to understand why this is happening.</p>
  
  <p>What am I doing incorrectly?
  I've also tried the above commands with pip 18.1 and 19.0.3 to the same end.</p>
  
  <p>I read the pip docs and found the following:</p>
  
  <blockquote>
    <p>Starting with v1.4, pip will only install stable versions as specified
    by pre-releases by default.</p>
    
    <p>The pip install command also supports a –pre flag that enables
    installation of pre-releases and development releases.</p>
    
    <p>--pre 
    Include pre-release and development versions. By default, pip only finds stable versions.</p>
  </blockquote>