From what I see, Yuzu itself is FLOSS (https://github.com/NixOS/nixpkgs/blob/73ad5f9e147c0d2a2061f1d4bd91e05078dc0b58/pkgs/applications/emulators/yuzu/base.nix#L77) and the Nintendo proprietary stuff is not shipped with it.
The licenses are also compliant, so I’m wondering why it is not built and cached by upstream cache.nixos.org.
CC-BY-ND-3.0 is a non-free license since it does not allow derivative works.
Note that CC-BY-ND-3.0 only applies to some of the icons used in the app. I’d honestly open an upstream issue on that.
Another possibility is to build all of the code in one derivation and then have a second derivation that adds the icons. The former would be Free, so hydra could build it. The latter is unfree but since it only adds a few icons, it could be built on the user’s macine in under a second.
Yes please. My machine is not too bad really, but Yuzu is heavy and needs a while to build. This solution sounds like best of both worlds. I will try to take on this task, but my Nix knowledge is limited enough that it will take me a while and if somebody wants to have a go I wouldn’t mind. Will even be a good example for me.
That sounds like a good task to get into Nix. Though I’d urge you to ask about this issue upstream first.
Using unfree assets is an issue and I don’t even want to know how the GPL plays into that. The icons aren’t really an essential component and could easily be substituted with any other that looks vaguely similar.
I’m confused how CC BY-ND 3.0 causes issues here. The images are used as-is and not “remixed, transformed, or built upon”
However I’d also add I’m not sure icons8 icons are actually CC BY-ND 3.0
depending on how scary the license is for the free yuzu bit you might need to remove the icons from your src download
another option is to join ryujinx gang
Not allowing derivative works means the license is non-free and hydra won’t touch it.
The derivation seems to have gotten their info from here: https://github.com/yuzu-emu/yuzu/blob/c50f2bd4f6797b778ae21dfed341129ed4a2252c/license.txt#L342-L365
But, looking at that license, it’s definitely not CC BY-ND but a custom non-free license. I have found hints that icons8 were CC BY-ND at some point though?
I think an upstream issue is more than necessary at this point.
I opened an issue the other day about the license not being great and that the old license might not even apply anymore
https://github.com/yuzu-emu/yuzu/issues/8077
Unrelated to this discussion they’ve swapped to GPLv3 to use some Apache 2.0 code and all the icon licensing is gone from the bottom of the license
The icons are still there though
All the icons are still there but the place to look for their licenses is different now: https://github.com/yuzu-emu/yuzu/blob/7382e7a5c811ec8ed4270818dcfe8bba357973b2/dist/license.md
Someone recently created a pull request for yuzu replacing the non-free icons with ones under Apache 2.0, MIT and CC0.
I applied this patch in nixpkgs, so now there is nothing in the way of cached binaries once it hits the channels 
Thanks a lot for following up and fixing!
Looks like PR is merged. The patch can be removed now.