title: Running the edX Developer Stack: Error on running paver lms
body: <p>I am following edx tutorial to run devstack(from <a href="http://edx-installing-configuring-and-running.readthedocs.org/en/latest/devstack/run_devstack.html#default-accounts-on-devstack" rel="nofollow">http://edx-installing-configuring-and-running.readthedocs.org/en/latest/devstack/run_devstack.html#default-accounts-on-devstack</a>) I am getting an error while running command "paver lms" .</p>
  
  <p>Error is as follow :</p>
  
  <pre><code>edxapp@precise64:~/edx-platform$ paver devstack lms
  ---&gt; pavelib.servers.devstack
  ---&gt; pavelib.prereqs.install_prereqs
  ---&gt; pavelib.assets.update_assets
  ---&gt; pavelib.prereqs.install_ruby_prereqs
  ---&gt; pavelib.prereqs.install_node_prereqs
  python manage.py lms --settings=devstack preprocess_assets
  Traceback (most recent call last):
    File "manage.py", line 15, in &lt;module&gt;
      from safe_lxml import defuse_xml_libs
  ImportError: No module named safe_lxml
  
  Captured Task Output:
  ---------------------
  
  ---&gt; pavelib.servers.devstack
  ---&gt; pavelib.prereqs.install_prereqs
  ---&gt; pavelib.assets.update_assets
  ---&gt; pavelib.prereqs.install_ruby_prereqs
  ---&gt; pavelib.prereqs.install_node_prereqs
  python manage.py lms --settings=devstack preprocess_assets
  
  Build failed running pavelib.servers.devstack: Subprocess return code: 1
  </code></pre>
  
  <p>Please guide me what needs to be done to run  the command.</p>