Building static files step error when upgrading

Perform a upgrade install, meet file existing bug:

Building cache of static files...
+ lava-server manage '--instance-template=/srv/lava/instances/{instance}/etc/lava-server/{{filename}}.conf' --instance=lab build_static --noinput --link
WARNING:root:This instance will not use sentry as SENTRY_DSN is not configured
WARNING:root:This instance will not use sentry as SENTRY_DSN is not configured
/srv/lava/instances/lab/lib/python2.6/site-packages/django/conf/__init__.py:75: DeprecationWarning: The ADMIN_MEDIA_PREFIX setting has been removed; use STATIC_URL instead.
  "use STATIC_URL instead.", DeprecationWarning)
Traceback (most recent call last):
  File "/srv/lava/instances/lab/bin/lava-server", line 9, in <module>
    load_entry_point('lava-server==0.13.dev', 'console_scripts', 'lava-server')()
  File "/srv/lava/instances/lab/src/lava-server/lava_server/manage.py", line 127, in main
    run_with_dispatcher_class(LAVAServerDispatcher)
  File "/srv/lava/instances/lab/lib/python2.6/site-packages/lava_tool/dispatcher.py", line 45, in run_with_dispatcher_class
    raise cls.run()
  File "/srv/lava/instances/lab/lib/python2.6/site-packages/lava/tool/dispatcher.py", line 147, in run
    raise SystemExit(cls().dispatch(args))
  File "/srv/lava/instances/lab/lib/python2.6/site-packages/lava/tool/dispatcher.py", line 137, in dispatch
    return command.invoke()
  File "/srv/lava/instances/lab/src/lava-server/lava_server/manage.py", line 115, in invoke
    execute_manager(settings, ['lava-server'] + self.args.command)
  File "/srv/lava/instances/lab/lib/python2.6/site-packages/django/core/management/__init__.py", line 459, in execute_manager
    utility.execute()
  File "/srv/lava/instances/lab/lib/python2.6/site-packages/django/core/management/__init__.py", line 382, in execute
    self.fetch_command(subcommand).run_from_argv(self.argv)
  File "/srv/lava/instances/lab/lib/python2.6/site-packages/django/core/management/base.py", line 196, in run_from_argv
    self.execute(*args, **options.__dict__)
  File "/srv/lava/instances/lab/lib/python2.6/site-packages/django/core/management/base.py", line 232, in execute
    output = self.handle(*args, **options)
  File "/srv/lava/instances/lab/lib/python2.6/site-packages/staticfiles/management/commands/build_static.py", line 90, in handle
    return super(Command, self).handle(*app_labels, **options)
  File "/srv/lava/instances/lab/lib/python2.6/site-packages/staticfiles/management/base.py", line 33, in handle
    return super(CommandLogger, self).handle(*args, **kwargs)
  File "/srv/lava/instances/lab/lib/python2.6/site-packages/staticfiles/management/base.py", line 78, in handle
    app_output = handle_method(app, **options)
  File "/srv/lava/instances/lab/lib/python2.6/site-packages/staticfiles/management/commands/build_static.py", line 125, in handle_app
    self.copy_file(path, prefix, storage, **options)
  File "/srv/lava/instances/lab/lib/python2.6/site-packages/staticfiles/management/commands/build_static.py", line 183, in copy_file
    os.symlink(source_path, destination_path)
OSError: [Errno 17] File exists
+ die 'Failed to update the cache of static content'
+ echo 'Failed to update the cache of static content'
Failed to update the cache of static content
+ exit 1