| 30 Jul 2021 |
 d4hines | In general, are there strategies for an "escape hatch" with NIx? That's something that worries me before I fully switch over to NixOS. | 16:17:10 |
| d4hines |
That's just a stylistic decision. At work we typically just stick to a single overlay.nix
Are there any open source examples you can share with me? I'd love to see an orchestration of nvfetcher, overlays, and flakes together.
| 16:18:53 |
 @timdeh:matrix.org | The fixed-output derivation could be considered a type of escape hatch, where the derivation is allowed to make network calls under the condition that the final result matches a user supplied hash. There is also the buildFHS helper to simulate a traditional FHS environment when needed. It's also pretty simple to declaratively spin up oci or docker containers when you need them as well. | 16:21:38 |
| @timdeh:matrix.org | as for a good example of nvfetcher, I just recently integrated my devos install with it (it was merged fairly recently). I haven't even pushed it yet, because I was working out some errors yesterday, but it's fully working now so I can probably push it here in a bit and send you a link. I've also been thinking about integrating nvfetcher at work for some of our vendored packages, but I haven't started that yet. | 16:22:45 |
 David Arnold (blaggacao) | In reply to @d4hines:matrix.org
Then, typically, somebody integrates that tool into nixpkgs to create a repo of all (or most) of the available packages
Wait, how does that work? Let's say it's npm2nix. There are dozens of versions of package X on npm that live side-by-side, but nixpkgs has exactly 1 version per version of nixpkgs, right?
I can recommend https://www.tweag.io/blog/2021-03-04-gomod2nix/ | 16:23:03 |
| David Arnold (blaggacao) | Very interesting discussion! So an intermediate resume would be (in order of "nixonicness"): *2nix -> nvfetcher -> fixed output with target ecosystem tooling | 16:28:50 |
| David Arnold (blaggacao) | My takeaway here is that nvfetcher can actually sit somewhere in the middleground, here | 16:29:46 |
| David Arnold (blaggacao) | (if that makes sense) | 16:29:57 |
| d4hines | At this stage very little Nix usage makes sense to me 😆 | 16:30:31 |
| d4hines | I've read through some of the Nix pills and I've gotten DevOS working, and that's about it. It's quite a learning curve | 16:30:56 |
| d4hines | So any concrete examples would be super appreciated | 16:31:20 |
| David Arnold (blaggacao) | RFC92 fit's in in that it "defers" evaluation of an "input from derivation" that wraps ecosystem tooling (like esy, etc.) so long as as a text hash of those defered insturctions can be always expected to produce the same outpu. | 16:32:31 |
| David Arnold (blaggacao) | * RFC92 fit's in in that it "defers" evaluation of an "input from derivation" that wraps ecosystem tooling (like esy, etc.) so long as as a text hash of those defered ecosystem instructions can be always expected to produce the same output | 16:32:52 |
| David Arnold (blaggacao) | (or at least that is my understanding of that RFC) | 16:33:57 |
| David Arnold (blaggacao) | In reply to @d4hines:matrix.org
I've read through some of the Nix pills and I've gotten DevOS working, and that's about it. It's quite a learning curve Honestly, I don't find the nix-pills super useful. But I guess we don't yet live up to rust standards in terms of docs 😃🦧 | 16:34:57 |
| d4hines | In reply to @blaggacao:matrix.org
Honestly, I don't find the nix-pills super useful. But I guess we don't yet live up to rust standards in terms of docs 😃🦧 Do you have any recommendations on how to get to "journeyman status" in Nix? | 16:36:11 |
 yusdacra | The only docs I've read was the manuals, was enough for me personally. I got bored of nix pills 😛 | 16:36:20 |
| yusdacra | Oh and reading nixpkgs derivations. | 16:36:35 |
| David Arnold (blaggacao) | In reply to @d4hines:matrix.org
Do you have any recommendations on how to get to "journeyman status" in Nix? For me, it was contributing to devos 😃😂 | 16:37:31 |
| David Arnold (blaggacao) | The biggest hurdle was 1) no good IDE support 2) really awkward tracing and debugging workflows. | 16:38:21 |
| d4hines | "infinite recursion encountered" lol | 16:38:45 |
| d4hines | That's what I get whenever I try to modify the overlay | 16:39:00 |
| David Arnold (blaggacao) | For tracing I find this flag useful: --override-input nixos path:/absolute/path/to/local/workdir/of/nixpkgs/with/a/few/traces | 16:39:47 |
| yusdacra | How does that help? | 16:40:11 |
| David Arnold (blaggacao) | ... at least it guarantees that you are eventually able to fijd the root cause without resorting to chances. | 16:40:38 |
| David Arnold (blaggacao) | * ... at least it guarantees that you are eventually able to find the root cause without resorting to chances. | 16:40:45 |
| David Arnold (blaggacao) | So I look at the backtraces and place a few traces in nixpkgs to understand what's really going on and then use that modified version of nixpkgs as an inout | 16:41:24 |
| David Arnold (blaggacao) | * So I look at the backtraces and place a few traces in nixpkgs to understand what's really going on and then use that modified version of nixpkgs as an input. | 16:41:36 |
| David Arnold (blaggacao) | * ... at least it guarantees that you are eventually able to find the root cause without resorting to rolling the dices. | 16:42:31 |
| David Arnold (blaggacao) | Gytis Ivaskevicius has made a PR to nix to eventually improve that situation. | 16:43:20 |
