Flake

[haras-unicorn]

I was going to add a package into nixpkgs for this but I realized the build step is a bit more complex than i liked so I went first to make this a flake and add a package via either cargo2nix or nixpkgs. This repo uses nix anyway and flakes are just a bit nicer way to setup a dev environment than just shell.nix IMO.

I am able to enter the shell but building with cargo gives me errors. It's rather long so I wont be posting that here.

I was not able to disable 32 bits for nixGL so I'd need a bit of help on that. I also replaced rustup with rustc and cargo since they're just faster to setup however that might lead to some issues.

[Kreyren]

Can you elaborate on the cargo2nix? It seems like kinda standard nixpkgs package via buildRustPackage (https://github.com/NixOS/nixpkgs/blob/master/doc/languages-frameworks/rust.section.md) to me?

[Kreyren]

Proposing to make a conditional check that uses impure on non-nixos setup and pure on nixos to keep the environment reproducible or some other management to avoid the impurity e.g. https://github.com/nix-community/nixGL?tab=readme-ov-file#install-nixgl which seems to install nixGL in the user profile, but i don't have much experience with it.

[haras-unicorn]

nixgl cannot be used purely right now - see this discussion nix-community/nixGL#90
the link you posted also suggests to use --impure
i also want it to be pure but i found no way of doing this right now
for some reason unknown to me nixgl uses builtins.currentTime which cannot be used purely
if you know of a way to make it work purely id be happy to make a change

[Kreyren]

I don't have a better solution atm. worst case if you are going to merge it with the --impure flag then i would suggest making an issue about it in verso for long-term tracking.

[Kreyren]

Well FWIW one way that comes to mind rn, but feels a bit hacky is to declaratively make a shell application via writeShellApplication alike how i do tasks in nixium https://github.com/NiXium-org/NiXium/tree/central/tasks/administration/build as the way i understand it is that the script creation happens during nix's eval phase that then executes the created script with it's environment outside of nix's build envrionment to have the ability to use impure things, but i literally looked into nixgl yesterday and didn't have time to test if this is a good solution yet

[haras-unicorn]

#157 added one rn so i dont forget

[haras-unicorn]

sry im not smart enough to understand everything ur saying
id like to merge it impurely right now as its better than just a shell.nix imo but let someone smarter take care of the purity - or myself when i learn more about nix

[Kreyren]

it's okay everyone sucks at nix :D I try to look into it as i am researching nixGL myself rn and if i find a way i try to submit it here as well

[haras-unicorn]

Can you elaborate on the cargo2nix? It seems like kinda standard nixpkgs package via buildRustPackage (https://github.com/NixOS/nixpkgs/blob/master/doc/languages-frameworks/rust.section.md) to me?

I use it to speed up development in personal projects.
And yes that is the standard for nixpkgs, but I found it is easier to use cargo2nix.
The reason is that cargo2nix and other 2nix projects cache the compilation of dependencies in the nix store.
So for example, you want to check if nix is building your project correctly via nix build.
If you use nix build with a buildRustPackage package it will have to compile all the dependencies every single time you make a change because the compilation of all of your dependencies is just a byproduct of the compilation of your package.
If you use nix build with cargo2nix the first time it will compile everything. The second time you use nix build after making a change it just compiles your project like cargo build because it cached the result of compilation of all of your dependencies.

In summary, if I was adding verso to nixpkgs i would use buildRustPackage as that is the standard there. But here, for development purposes, I can use cargo2nix to cache compilation of dependencies and package this project in fewer lines of code.

[Kreyren]

Fair

[wusyong]

Hey, FYI, we probably will only support Flatpak for now.
Nix support serves only for development purposes. shell.nix is inspired by what Servo has.
There are still some dependency challenges in Nix that I think are worth mentioning if you want to push flake support:

• Gstreamer
• LLVM (which is stuck in v14)
• X11/Wayland
• GL driver and libraries

I think we can revisit this again once nix-community/nixGL#90 is resolved as you mentioned in #157

[Kreyren]

I think we can revisit this again once nix-community/nixGL#90 is resolved as you mentioned in #157 -- @wusyong (#155 (comment))

That is not a blocking issue that would prevent functionality and only affects non-NixOS systems.. it's kinda a nice to have thing to make the shell more reproducible.