@LarsGit223 Thanks, I was confused by the [GP_CHECK_PLUGIN_GTK**3_ONLY**](https://github.com/geany/geany-plugins/pull/697/files#diff-c6ec9ad09f6351d19...).
P.S. I use Xubuntu 17.10, but I compile on my own (I use [PR 1752](https://github.com/geany/geany/pull/1752)) and [I don't like GTK3](https://github.com/geany/geany/issues/1746).