title: using fabric to change LD_LIBRARY_PATH
body: <p>when i login a remote server through ssh, i see the LD_LIBRARY_PATH was :</p>
  
  <pre><code>echo $LD_LIBRARY_PATH
  :/usr/local/lib
  </code></pre>
  
  <p>And when i use fabric in python, to run the same code in fabric run api, the result is empty.</p>
  
  <pre><code>from fabric.api import *
  def test():
      run("echo $LD_LIBRARY_PATH")
  </code></pre>
  
  <p>and even when i try to change the LD_LIBRARY_PATH using fabric, it doesn't work at all.</p>
  
  <pre><code>from fabric.api import *
  def test():
      run("echo $LD_LIBRARY_PATH")
      run("export LD_LIBRARY_PATH=/usr/local/lib:$LD_LIBRARY_PATH")
  </code></pre>
  
  <p>Does anyone know why?</p>