Comment 3 for bug 1680891

The doc you link to is old, but it is current as far as I'm aware. A manual is available now too, although the section covering plugins is a copy and paste from the tenshu one: http://terminator-gtk3.readthedocs.io/en/latest/plugins.html#creating-your-own-plugins

Nothing special for coding plugins. Just bash on it till you think it works, test, find bugs, repeat.

The standard "-d" flag can be used for debugging, although typically the plugins don't have a lot of debug statements. You can narrow it down by passing "--debug-classes SSHMenu" which would only give debug output from the plugin. However you'll need to add debug statements first as SSHMenu doesn't have any.