@2chilled, thanks for your PR! By analyzing the history of the files in this pull request, we identified @the-kenny, @viric and @aske to be potential reviewers.

The GTK2 version of RawTherapee is on life support. It won't be maintained going forward and GTK3 is what is being currently developed and deployed.

Why stick to GTK2?

@paperdigits right now it's a workaround. I tried the gtk3 version (it builds fine after replacing a few dependencies) but looks horrible for some reason (missing themes, icons, etc. - I'm not entirely sure what causes this) and I didn't have the time to hunt down these issues.

That said, I'd accept a PR to switch to the gtk3 version any time.

@2chilled Any thoughts on my comment earlier? I'm not sure if there's a point in adding this suffix at all - to me it seems like it doesn't provide any benefit (as it doesn't really matter in nixpkgs if a package depends on gtk2 or gtk3 - dependencies are handled transparently)

@the-kenny the GTK3 version needs at least GTK 3.22 for the theme to work. I was thinking that the version of GTK was <3.22, but I didn't have time to investigate.

I've been trying to get photography related tools all up-to-date, as I'd like to switch my editing machine to NixOS :)

@paperdigits Our rawtherapee is up to date, and I'm sure we can switch to the gtk3 branch at some point :) What other tools are you using in your workflow (personal interest here)?

@the-kenny Cool, I'm sure we can switch to GTK3 once the GTK+ package gets to 3.22, right now it seems to be at 3.20.

I'm using Darktable, RawTherapee, Hugin/enfuse (which isn't built with openMP/GPU support by default in nix), Geeqie, G'MIC, and GIMP 2.9.x (currently not packaged). Less frequently I use Luminance HDR. I need to get DisplayCAL, and HDR Merge packaged.

If you have interest in photography, please join us at https://discuss.pixls.us -- many devs and users of all sorts of FOSS programs there. Same for you @2chilled, please join us.

Seems like we have support for gtk 3.22 now, so I'll try a gtk3 build.

@the-kenny I'll remove the suffix to keep nix-env -u healthy. Thanks for pointing that out.

@the-kenny @paperdigits gtk3 version works and looks very nice on my system!

Trying it now!

Sorry for the late response. I had to mnually adjust the font size from 10 down to 8, but I'm quite sure that's caused by me using this font size for the gtk2 build (gtk2 likely isn't high-dpi compatible).

LGTM, merging now.

@2chilled this is awesome! Thank you!