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For context, this particular article is a cool deep dive into how Nix works, but it doesn't represent what using Nix + Nixpkgs is like in practice. I've been us

For context, this particular article is a cool deep dive into how Nix works, but it doesn't represent what using Nix + Nixpkgs is like in practice. I've been using Nix personally and professionally for almost 10 years now (yikes has time passed quickly!) and I have never needed to operate at the level of derivations like this.

setheron 2y ago
Professionally for 10 years ? I would like to hear more. I remember Target funded some earlier Nix work like lorri. Interestingly, I found operating at this level to have been a necessity if I wanted to fix or write a derivation. Otherwise I would face random errors and be left clueless as to what the problem was. Writing a derivation builder (nix pill) was illuminating.
- tikhonj 2y ago
  Yep, I was one of the people who originally started using Nix on that particular team at Target back in 2016. I wasn't the only person interested in Nix but, if I'm recalling correctly, I was the person who first set it up and supported our Nix environment on Linux and macOS for the first year or two. After we scaled up a bit we hired some more Nix-focused people and some consultants (for stuff like lorri), so I stopped having to do much Nix stuff day-to-day. That was a really special team. Nobody "let" me use Nix, we just did it because it made sense to us, and I went out of my way to support it internally not because I felt pressured to do it, but because I was enthusiastic about making it work. The culture there reminded me of this story[1] about getting Python into production at Goldman—and it turns out that the VP who built the supply chain team at Target started his career in strats at Goldman and was heavily inspired by the same Armen from that story :) [1]: https://news.ycombinator.com/item?id=29104401 https://news.ycombinator.com/item?id=29104401 After leaving Target, I also used Nix for my own work setup at CX Score. That was a seed-stage startup and I didn't want to push Nix on anybody else, but it made my own work setup much nicer. Most recently I moved to Mercury where we use Nix at a pretty big scale (several hundred developers). We have a team that handles most of it so I haven't had to do much myself, but I've helped a few people work through Nix issues just because I could :) I'm also one of the weirdos who uses NixOS on my work laptop instead of getting a macbook. And, in parallel, I've been using NixOS on all my personal machines ever since I first discovered it. That was relatively shortly before joining Target, so, if I had to guess, late 2015 or early 2016. Coming up on 10 years shortly, even though it really does not feel like it...
  - pkulak 2y ago
    I still have a Thinkpad from 2015 for work that I run NixOS on. Company policy has since changed to Mac only, but I think I’ve got at least another decade on this ol’ gal. I suppose I could use Nix Darwin, but it wouldn’t be the same.
  - nylonstrung 2y ago
    That's so cool! I love NixOS and was excited to see Mercury using it. What made Mercury choose it and what have the advantages been for a company like that?
    - tikhonj 2y ago
      I don't have a great read on how it happened at Mercury originally; I assume that they started using it near the beginning since lots of Haskellers like Nix and it solves some pain points with packaging, and they've been using it ever since. The key insight is that it's been able to scale and still work pretty well even as Mercury is hitting a few hundred developers. There's a bit of friction here and there, but the overall dev experience is pretty good; in a number of ways, it's distinctly better than what I've seen in places that heavily use Docker.
      - nylonstrung 2y ago
        Very interesting! It's cool to see some of the most cutting edge infra teams coming around to a tool that came well before Docker. Since you're presumably using nixos VMs a lot, I'd be curious if you have any thoughts on this project. It's Nix hypervisor + microvms as an alternative to containers https://github.com/astro/microvm.nix https://github.com/astro/microvm.nix
- microtonal 2y ago
  Interestingly, I found operating at this level to have been a necessity if I wanted to fix or write a derivation. Otherwise I would face random errors and be left clueless as to what the problem was. I have used Nix on and off for work since 2018. We are using Nix at my current employer for two projects. I agree that if you want to go beyond some simple dev shells, for any realistically complex project you really need Nix Pills-level understanding (+ a good idea of how things work in nixpkgs). It's a two-edged sword - the learning curve is very steep, but once you have that level of understanding, it's a superpower. We heavily use CUDA/ROCm machine learning stacks and Nix makes it much easier to ensure everyone is using the same development environment. Switching between different branches that may have different sets of dependencies/dependency versions always works. Also, it's much easier to stack custom patches on dependencies and caching avoids all the rebuilds.
gadtfly 2y ago
Completely unrelated to anything I'm just taking this as an opportunity to yell this into the void while nix is on topic: I have a theory that a problem for Nix understanding and adoption out of all apparent proportion is its use of ; in a way that is just subtly, right in the uncanny valley, different from what ; means in any other language. In the default autogenerated file everyone is given to start with, it immediately hits you with: environment.systemPackages = with pkgs; [ foo ]; How is that supposed to read as a single expression in a pure functional language?
- eru 2y ago
  > How is that supposed to read as a single expression in a pure functional language? Well, in Haskell the following is technically single expression: do with pkgs; [ foo ]; (Eg using 'let {with = pure; pkgs = 1; foo = 2}' makes the above type check and compile.) But extreme nerdery and nit-picking aside, I agree that the choice of syntax in nix unfortunate here.
- 418tpot 2y ago
  I agree the syntax isn't perfect, but in case you're actually confused there's really only 3 places where semicolons go, and I would argue that two of the places make a lot of sense— as a terminator for attribute sets, and a terminator for `let` declarations. Unfortunately it is also used with the somewhat confusing `with` operator which I personally avoid using. For those of you who aren't familiar, it works similar to the now deprecated javascript `with` statement where `with foo; bar` will resolve to `bar` if it is in scope, otherwise it will resolve to `foo.bar`.
  - pkulak 2y ago
    Your p,k,g,s keys must be worn to nubs.
  - wiktor-k 2y ago
    > now deprecated javascript `with` statement where `with foo; bar` will resolve to `bar` if it is in scope, otherwise it will resolve to `foo.bar`. Technically, in JavaScript it's `with (foo) bar`. Source: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/with https://developer.mozilla.org/en-US/docs/Web/JavaScript/Refe...

setheron 2y ago

Professionally for 10 years ? I would like to hear more. I remember Target funded some earlier Nix work like lorri. Interestingly, I found operating at this level to have been a necessity if I wanted to fix or write a derivation. Otherwise I would face random errors and be left clueless as to what the problem was. Writing a derivation builder (nix pill) was illuminating.

tikhonj 2y ago
Yep, I was one of the people who originally started using Nix on that particular team at Target back in 2016. I wasn't the only person interested in Nix but, if I'm recalling correctly, I was the person who first set it up and supported our Nix environment on Linux and macOS for the first year or two. After we scaled up a bit we hired some more Nix-focused people and some consultants (for stuff like lorri), so I stopped having to do much Nix stuff day-to-day. That was a really special team. Nobody "let" me use Nix, we just did it because it made sense to us, and I went out of my way to support it internally not because I felt pressured to do it, but because I was enthusiastic about making it work. The culture there reminded me of this story[1] about getting Python into production at Goldman—and it turns out that the VP who built the supply chain team at Target started his career in strats at Goldman and was heavily inspired by the same Armen from that story :) [1]: https://news.ycombinator.com/item?id=29104401 https://news.ycombinator.com/item?id=29104401 After leaving Target, I also used Nix for my own work setup at CX Score. That was a seed-stage startup and I didn't want to push Nix on anybody else, but it made my own work setup much nicer. Most recently I moved to Mercury where we use Nix at a pretty big scale (several hundred developers). We have a team that handles most of it so I haven't had to do much myself, but I've helped a few people work through Nix issues just because I could :) I'm also one of the weirdos who uses NixOS on my work laptop instead of getting a macbook. And, in parallel, I've been using NixOS on all my personal machines ever since I first discovered it. That was relatively shortly before joining Target, so, if I had to guess, late 2015 or early 2016. Coming up on 10 years shortly, even though it really does not feel like it...
- pkulak 2y ago
  I still have a Thinkpad from 2015 for work that I run NixOS on. Company policy has since changed to Mac only, but I think I’ve got at least another decade on this ol’ gal. I suppose I could use Nix Darwin, but it wouldn’t be the same.
- nylonstrung 2y ago
  That's so cool! I love NixOS and was excited to see Mercury using it. What made Mercury choose it and what have the advantages been for a company like that?
  - tikhonj 2y ago
    I don't have a great read on how it happened at Mercury originally; I assume that they started using it near the beginning since lots of Haskellers like Nix and it solves some pain points with packaging, and they've been using it ever since. The key insight is that it's been able to scale and still work pretty well even as Mercury is hitting a few hundred developers. There's a bit of friction here and there, but the overall dev experience is pretty good; in a number of ways, it's distinctly better than what I've seen in places that heavily use Docker.
    - nylonstrung 2y ago
      Very interesting! It's cool to see some of the most cutting edge infra teams coming around to a tool that came well before Docker. Since you're presumably using nixos VMs a lot, I'd be curious if you have any thoughts on this project. It's Nix hypervisor + microvms as an alternative to containers https://github.com/astro/microvm.nix https://github.com/astro/microvm.nix
microtonal 2y ago
Interestingly, I found operating at this level to have been a necessity if I wanted to fix or write a derivation. Otherwise I would face random errors and be left clueless as to what the problem was. I have used Nix on and off for work since 2018. We are using Nix at my current employer for two projects. I agree that if you want to go beyond some simple dev shells, for any realistically complex project you really need Nix Pills-level understanding (+ a good idea of how things work in nixpkgs). It's a two-edged sword - the learning curve is very steep, but once you have that level of understanding, it's a superpower. We heavily use CUDA/ROCm machine learning stacks and Nix makes it much easier to ensure everyone is using the same development environment. Switching between different branches that may have different sets of dependencies/dependency versions always works. Also, it's much easier to stack custom patches on dependencies and caching avoids all the rebuilds.

gadtfly 2y ago

Completely unrelated to anything I'm just taking this as an opportunity to yell this into the void while nix is on topic: I have a theory that a problem for Nix understanding and adoption out of all apparent proportion is its use of ; in a way that is just subtly, right in the uncanny valley, different from what ; means in any other language. In the default autogenerated file everyone is given to start with, it immediately hits you with: environment.systemPackages = with pkgs; [ foo ]; How is that supposed to read as a single expression in a pure functional language?

eru 2y ago
> How is that supposed to read as a single expression in a pure functional language? Well, in Haskell the following is technically single expression: do with pkgs; [ foo ]; (Eg using 'let {with = pure; pkgs = 1; foo = 2}' makes the above type check and compile.) But extreme nerdery and nit-picking aside, I agree that the choice of syntax in nix unfortunate here.
418tpot 2y ago
I agree the syntax isn't perfect, but in case you're actually confused there's really only 3 places where semicolons go, and I would argue that two of the places make a lot of sense— as a terminator for attribute sets, and a terminator for `let` declarations. Unfortunately it is also used with the somewhat confusing `with` operator which I personally avoid using. For those of you who aren't familiar, it works similar to the now deprecated javascript `with` statement where `with foo; bar` will resolve to `bar` if it is in scope, otherwise it will resolve to `foo.bar`.
- pkulak 2y ago
  Your p,k,g,s keys must be worn to nubs.
- wiktor-k 2y ago
  > now deprecated javascript `with` statement where `with foo; bar` will resolve to `bar` if it is in scope, otherwise it will resolve to `foo.bar`. Technically, in JavaScript it's `with (foo) bar`. Source: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/with https://developer.mozilla.org/en-US/docs/Web/JavaScript/Refe...