[btobolaski]

I’ve been using nixos for a solid 2 years. I was introduced to nix 5 years ago when a developer at a company I worked for introduced it for one of the developer environments. In those 3 intervening years, I went from thinking that nix was incredibly stupid to thinking that nix had some good ideas and I should try it. All of that is to say, that I have some knowledge of nix. I think most of the criticisms are fair.

Developer environments are my favorite usage of nix. To me, they deliver on the promise but, there’s a big caveat, dealing with languages that need native libraries is a real pain. The mentioned buildFHSUserEnv is basically a last resort. There are better solutions but they require a great deal more fiddling. I find that my start up time for getting a developer environment going is very long, sometimes 10x longer than just installing it in Ubuntu on a fresh vm. I find it is worthwhile to go through this process as I then don’t have to worry about being able to recreate it or switch between very incompatible projects. Luckily for me, the ecosystem that I frequently have to deal with this with is python and poetry2nix works pretty well (with some rough edges). mach-nix made this even easier but it is abandoned in favor of dream2nix which isn’t ready.

The learning curve for nix is intense. It is incredibly unfamiliar and useful information is widely spread (the main documentation was too dense for me to comprehend when I started). Read the post, it seems to me that the author never got over the learning hump into it actually being useful. I think that is a perfectly rational choice, it isn’t the right thing for everyone. The one thing that kept me going through the first year of the learning process was one of the things that the author didn’t find important, being able to boot to a previous configuration. I don’t have to worry about updates that break something or making a bad configuration change. If I update my system and something breaks, at worst, I can simply reboot to revert to the previous configuration until I’m ready to troubleshoot the issue.

Nix also does itself a disservice but not promoting flakes as the nix way. Using channels makes reproducibility much worse.

[kourtni]

@btobolaski, I'm most interested in nix for creating reproducible dev environments. Do you have any public Python/Poetry2Nix projects on Github that I can look at?

[btobolaski]

Eh, sure. These aren’t exactly made for public consumption but you might find them helpful. They don’t have documentation so you’ll have to do investigation yourself.

https://github.com/btobolaski/mood-tracker

Very basic Django app. Poetry2Nix basically worked out of the box without fiddling. Can drop into a dev shell with `nix develop`. It also demonstrates building a container for the application with exactly the same dependencies using `nix build`

https://github.com/btobolaski/text-generation-webui/tree/nix...

The opposite end of the spectrum, this adds a nix dev environment for text-generation-webui with cuda support. It is much more complex and mixes wheels with python libraries from nixpkgs. Torch comes from nixpkgs which means that it needs to build from source which takes a while. I’m currently attempting to get it working with just wheels but I’m having some trouble getting all of the native library paths fixed. This demonstrates nix’s flexibility as it pulls two separate copies of nixpkgs in order to match cuda and the nvidia drivers to what my hardware is currently running with.