title: pip install package from url
body: <pre><code>pip install http://www.crummy.com/software/BeautifulSoup/unreleased/4.x/BeautifulSoup-4.0b.tar.gz
  </code></pre>
  
  <p>this installs package bs4, and everything is ok. But if I add this line to requirements.txt</p>
  
  <pre><code>http://www.crummy.com/software/BeautifulSoup/unreleased/4.x/BeautifulSoup-4.0b.tar.gz
  </code></pre>
  
  <p>and run</p>
  
  <pre><code>pip install -r requirements.txt
  </code></pre>
  
  <p>the output is</p>
  
  <pre><code>  Downloading/unpacking http://www.crummy.com/software/BeautifulSoup/unreleased/4.x/BeautifulSoup-4.0b.tar.gz (from -r requirements.txt (line 40))
    Downloading BeautifulSoup-4.0b.tar.gz (42Kb): 42Kb downloaded
    Running setup.py egg_info for package from http://www.crummy.com/software/BeautifulSoup/unreleased/4.x/BeautifulSoup-4.0b.tar.gz
  </code></pre>
  
  <p>but the package doesn't get installed.</p>
  
  <pre><code>&gt;&gt;&gt; import bs4
  Traceback (most recent call last):
    File "&lt;stdin&gt;", line 1, in &lt;module&gt;
  ImportError: No module named bs4
  </code></pre>