Is not this overkill? Why not just use the maintained library?

@jtojnar GTK3? My thought was as long as there is Xfce 4.12 around GTK2 support should be kept and I decided against switching the default for now. I'm totally fine on defaulting to GTK3 but at least option for GTK2 should be kept for some time IMHO

This PR doesn't add support for anything, it just renames parameters and changes code formatting. It seems like you can already do everything you want in current nixpkgs: geany.override { gtk2 = gtk3; }

Is it possible to just switch to gtk3? Renaming gtk2 to gtk doesn't magically add support for gtk3. In my mind, support means that we are building those variants and fixing them when needed. If you are willing to (co-)maintain geany, I don't see a problem why we can't build both gtk2 and gtk3 versions.

cc @frlan as geany maintainer

When building with GTK3, we will also need to add wrapGAppsHook to dependencies so the relevant settings can be found.

@jtojnar Good point. And that currently breaks darwin build, IIRC. So then this PR is incomplete because it doesn't implement wrapGAppsHook?

Yup. Without wrapGAppsHook, the file chooser dialogue might crash the application due to missing GSettings schemas.

@frlan are you able to address the above comments and continue with this PR?

Yes, I will.