Ubiquity 16.10.9~ppa5
Traceback (most recent call last):
  File "/usr/lib/ubiquity/bin/ubiquity", line 649, in <module>
    main(oem_config)
  File "/usr/lib/ubiquity/bin/ubiquity", line 633, in main
    install(args[0], query=options.query)
  File "/usr/lib/ubiquity/bin/ubiquity", line 256, in install
    ', '.join(frontends))