title: Why can't `virtualenv` find `pkg_resources`?
body: <p>I'm trying to use virtualenv in Ubuntu to install a local virtual Python environment.  When I run the shell command:</p>
  
  <pre><code>$ virtualenv ./virt_python
  </code></pre>
  
  <p>It throws an exception that it can't import <code>pkg_resources</code>.  But when I open a Python shell and <code>from pkg_resources import load_entry_point</code> it runs fine.  For reference, the complete stacktrace is below.</p>
  
  <pre><code>$ virtualenv ./virt_python
  New python executable in ./virt_python/bin/python
  Installing setuptools............done.
  Installing pip.......
    Complete output from command /home/rpsharp/local/...hon/bin/easy_install /usr/local/lib/pytho...pport/pip-1.1.tar.gz:
    Traceback (most recent call last):
    File "/home/rpsharp/local/workspace/invest-natcap.invest-3/virt_python/bin/easy_install", line 5, in &lt;module&gt;
      from pkg_resources import load_entry_point
  ImportError: No module named pkg_resources
  ----------------------------------------
  ...Installing pip...done.
  Traceback (most recent call last):
    File "/usr/local/bin/virtualenv", line 9, in &lt;module&gt;
      load_entry_point('virtualenv==1.7.1.2', 'console_scripts', 'virtualenv')()
    File "/usr/local/lib/python2.6/dist-packages/virtualenv.py", line 928, in main
      never_download=options.never_download)
    File "/usr/local/lib/python2.6/dist-packages/virtualenv.py", line 1042, in create_environment
      install_pip(py_executable, search_dirs=search_dirs, never_download=never_download)
    File "/usr/local/lib/python2.6/dist-packages/virtualenv.py", line 640, in install_pip
      filter_stdout=_filter_setup)
    File "/usr/local/lib/python2.6/dist-packages/virtualenv.py", line 1006, in call_subprocess
      % (cmd_desc, proc.returncode))
  OSError: Command /home/rpsharp/local/...hon/bin/easy_install /usr/local/lib/pytho...pport/pip-1.1.tar.gz failed with error code 1
  </code></pre>
  
  <p>I tried the solution proposed here <a href="https://stackoverflow.com/a/10538412/42897">https://stackoverflow.com/a/10538412/42897</a> but it didn't have any effect.</p>