Comment 7 for bug 890783

> and check whether it prompts you to install
> additional packages. If it does, that should
> fix your problem.

It doesn't. Although this will install some language related packages it will not fix the problem with git-gui.

Steps to reproduce:

* Install fresh xubuntu 16.04 (choose non-english language during install)
* install git and git-gui
* $ git gui
  -> modal warning about missing spell check pops up every time

* open language settings
  -> some additional packages will be automatically installed
  -> git gui warning still pops up

* install aspell-de (or whatever other language you have)
  -> git gui warning disappears