[[https://hangouts.google.com/|Google Hangouts]] is supported using [[HowtoPurple|libpurple]], which in turn needs another plugin, [[https://bitbucket.org/EionRobb/purple-hangouts|purple-hangouts]].

You need to build Bitlbee using `libpurple` support, and you need to install the `purple-hangouts` plugin for `libpurple`!

If you are using a Mac, see [[HowtoHangoutsMacOS|Howto Hangouts on macOS Sierra]].