code: def check_dependencies():
      
  
      print 'Checking dependencies...'
      if not HAS_VIRTUALENV:
          print 'Virtual environment not found.'
          # Try installing it via easy_install...
          if HAS_EASY_INSTALL:
              print 'Installing virtualenv via easy_install...',
              run_command(['easy_install', 'virtualenv'],
                          die_message='easy_install failed to install virtualenv'
                                      '\ndevelopment requires virtualenv, please'
                                      ' install it using your favorite tool')
              if not run_command(['which', 'virtualenv']):
                  die('ERROR: virtualenv not found in path.\n\ndevelopment '
                      ' requires virtualenv, please install it using your'
                      ' favorite package management tool and ensure'
                      ' virtualenv is in your path')
              print 'virtualenv installation done.'
          else:
              die('easy_install not found.\n\nInstall easy_install'
                  ' (python-setuptools in ubuntu) or virtualenv by hand,'
                  ' then rerun.')
      print 'dependency check done.'
docs: Make sure virtualenv is in the path.