UndefinedError: 'page_title' is undefined

[kkamkou]

https://sentry.io/twoka/gitmostwantedcom/issues/354669856/

UndefinedError: 'page_title' is undefined
(8 additional frame(s) were not displayed)
...
  File "flask/templating.py", line 110, in _render
    rv = template.render(context)
  File "jinja2/environment.py", line 989, in render
    return self.environment.handle_exception(exc_info, True)
  File "jinja2/environment.py", line 754, in handle_exception
    reraise(exc_type, exc_value, tb)
  File "jinja2/_compat.py", line 37, in reraise
    raise value.with_traceback(tb)
  File "/var/www/gitmostwanted.com/gitmostwanted/templates/repository/top.html", line 10, in top-level template code
    {% set page_title = page_title + ' (solid)' %}

UndefinedError: 'page_title' is undefined