title: Ubuntu: QXcbConnection: Could not connect to display Could not connect to any X display
body: <p>OS Error
  wkhtmltopdf exited with non-zero code 1. error:
  QStandardPaths: XDG_RUNTIME_DIR not set, defaulting to '/tmp/runtime-root'
  qt.qpa.screen: QXcbConnection: Could not connect to display 
  Could not connect to any X display.</p>