!RbXGJhHMsnQcNIDFWN:nixos.org

Haskell in Nixpkgs/NixOS

707 Members
For discussions and questions about Haskell with Nix, cabal2nix and haskellPackages in nixpkgs | Current Docs: https://haskell4nix.readthedocs.io/140 Servers

Load older messages


SenderMessageTime
9 Dec 2025
@andromeda:tchncs.deandromedaso like MangoIV said I would be using Cabal as the 'source of truth' and Nix just as a convenience dev environment for those who have it.09:16:05
@maralorn:maralorn.demaralornAh, I see09:16:24
@andromeda:tchncs.deandromedaNix's flexibility is a blessing and a curse xD09:16:49
@maralorn:maralorn.demaralornMy best flake is probably this one others might have cleaner ones: https://github.com/maralorn/nix-output-monitor/blob/main/flake.nix09:19:33
@maralorn:maralorn.demaralornBut I am not saying that everything in there is recommended for every project09:20:20
@andromeda:tchncs.deandromedayo you write nom!? Awesome! I use it every day09:20:38
@maralorn:maralorn.demaralornAnyway the spirit of nixpkgs is generally to reuse language specific build instructions instead of dodging them.09:22:33
@maralorn:maralorn.demaralornThis is imo not a failure to separate concerns09:22:51
@maralorn:maralorn.demaralornnix does not know anything about Haskell or cabal09:23:14
@maralorn:maralorn.demaralornBut nixpkgs is a suite of libraries to build projects from all kinds of ecosystems. Using such a library to build a Haskell package seems smart to me instead of redundant.09:24:32
@andromeda:tchncs.deandromedaI love that despite there being a 'right' way to do Nix, it's such a powerful and general tool that you can go literal years doing it the 'wrong' way without a hitch09:27:29
@maralorn:maralorn.demaralornAlso your approach seems slightly dishonest because when you use ghcWithPackages you still rely on tons of packages being built with our Cabal based builder and e.g. it uses bespoke code to put a DB in your environment which cabal-install understands. So you are not really getting rid of the layer mangling you are complaining about.09:28:11
@maralorn:maralorn.demaralornThat being said no one is stoping you from doing it your way. 😆09:29:00
@maralorn:maralorn.demaralornI personally think that the redundancy of the usual approach is not a problem. Because all the redundant information can be auto-generated on the nix side by cabal2nix.09:32:14
@andromeda:tchncs.deandromeda this is where I am now, I'll shift it to a Cabal-centered approach after school. Lmk if you have any other cool tips! 09:35:32
@morj:morj.menMorj joined the room.10:44:13
@andromeda:tchncs.deandromedaI lied I'm going to mess around with FFI to see if I can get RGFW working instead of GLFW :)18:57:59
@andromeda:tchncs.deandromedaOk so it's not working. I've been trying to troubleshoot for a while... maybe it's the way I've linked dependent libraries? Maybe it's a type error in my FFI? A brief look-around by someone smarter than me would be greatly appreciated... one again ignore the atrocities that are the build process... https://git.mtgmonkey.net/Andromeda/hs-rgfw22:01:48
@andromeda:tchncs.deandromedathe problem is that a window doesn't appear and window_shouldClose is immediately false, leading me to believe a type representation error or a windowing dependency error has occuredd22:03:19
10 Dec 2025
@andromeda:tchncs.deandromedaonce I remove the #define RGFW_WAYLAND it works for 1 frame on an X window manager (namely x monad)05:08:00
@andromeda:tchncs.deandromedaor better if I define ..WAYLAND and ..X11 then it automatically falls back05:12:45
@andromeda:tchncs.deandromedabut still only one frame05:12:56
@andromeda:tchncs.deandromedathis is really embarassing but I mixed up which exit code-style function return was good (==0) and bad (/=0)05:21:11
@mequbic:matrix.orgiqubic (she/her) So I have the Haskell package sbv listed as a dependency of my project in my Cabal file and then I'm pulling that in with cabal2Nix. For some reason, Nix is trying to pull in sbv-11.7 which is A) old and B) broken. Is there some way I can tell Nix to get version 13.3 for me? 09:52:54
@mequbic:matrix.orgiqubic (she/her)https://hackage.haskell.org/package/sbv09:52:59
@mequbic:matrix.orgiqubic (she/her)
{ pkgs ? import <nixpkgs> {} }:
let
  src = pkgs.nix-gitignore.gitignoreSource [] ./.;
  myPkg = pkgs.haskell.packages.ghc912.callCabal2nix "aoc25" src {};
in
pkgs.stdenv.mkDerivation {
  name = "aoc-shell";

  buildInputs = [
    myPkg.env.nativeBuildInputs

    pkgs.cabal-install
    pkgs.haskell.packages.ghc912.haskell-language-server

    pkgs.z3
  ];
}
09:53:12
@toonn:matrix.orgtoonn I think you'll have to override the package. Probably best to check the Nixpkgs manual because it's tricky. 10:04:22
@maralorn:maralorn.demaralorniqubic if none of your dependencies need sbv you can get away with putting the override in the empty attrset at the end of your line 4.10:05:34
@maralorn:maralorn.demaralornThere might be a ...ghc912.sbv_13_3 attribute which you can use.10:07:32
@maralorn:maralorn.demaralornAlthough it might also be broken without intervention.10:07:51

Show newer messages


Back to Room ListRoom Version: 6