title: Could not find a version that satisfies the requirement <package>
body: <p>I'm installing several Python packages in Ubuntu 12.04 using the following <code>requirements.txt</code> file:</p>
  
  <pre><code>numpy&gt;=1.8.2,&lt;2.0.0
  matplotlib&gt;=1.3.1,&lt;2.0.0
  scipy&gt;=0.14.0,&lt;1.0.0
  astroML&gt;=0.2,&lt;1.0
  scikit-learn&gt;=0.14.1,&lt;1.0.0
  rpy2&gt;=2.4.3,&lt;3.0.0
  </code></pre>
  
  <p>and these two commands:</p>
  
  <pre><code>$ pip install --download=/tmp -r requirements.txt
  $ pip install --user --no-index --find-links=/tmp -r requirements.txt
  </code></pre>
  
  <p>(the first one downloads the packages and the second one installs them).</p>
  
  <p>The process is frequently stopped with the error:</p>
  
  <pre><code>  Could not find a version that satisfies the requirement &lt;package&gt; (from matplotlib&lt;2.0.0,&gt;=1.3.1-&gt;-r requirements.txt (line 2)) (from versions: )
  No matching distribution found for &lt;package&gt; (from matplotlib&lt;2.0.0,&gt;=1.3.1-&gt;-r requirements.txt (line 2))
  </code></pre>
  
  <p>which I fix manually with:</p>
  
  <pre><code>pip install --user &lt;package&gt;
  </code></pre>
  
  <p>and then run the second <code>pip install</code> command again.</p>
  
  <p>But that only works for <em>that</em> particular package. When I run the second <code>pip install</code> command again, the process is stopped now complaining about <em>another</em> required package and I need to repeat the process again, ie: install the new required package manually (with the command above) and then run the second <code>pip install</code> command.</p>
  
  <p>So far I've had to manually install <code>six</code>, <code>pytz</code>, <code>nose</code>, and now it's complaining about needing <code>mock</code>.</p>
  
  <p>Is there a way to tell <code>pip</code> to automatically install <em>all</em> needed dependencies so I don't have to do it manually one by one?</p>
  
  <p><strong>Add</strong>: This only happens in Ubuntu 12.04 BTW. In Ubuntu 14.04 the <code>pip install</code> commands applied on the <code>requirements.txt</code> file work without issues.</p>