!RbXGJhHMsnQcNIDFWN:nixos.org

Haskell in Nixpkgs/NixOS

697 Members
For discussions and questions about Haskell with Nix, cabal2nix and haskellPackages in nixpkgs | Current Docs: https://nixos.org/manual/nixpkgs/unstable/#haskell | Current PR: https://github.com/nixos/nixpkgs/pulls?q=is%3Apr+is%3Aopen+head%3Ahaskell-updates | Maintainer Docs: https://github.com/NixOS/nixpkgs/blob/haskell-updates/pkgs/development/haskell-modules/HACKING.md | More Nix: #community:nixos.org | More Haskell: #haskell-space:matrix.org | Merger Schedule: https://cloud.maralorn.de/apps/calendar/p/H6migHmKX7xHoTFa/dayGridMonth/now | Join #haskell.nix:libera.chat for question about the alternative haskell.nix infrastructure138 Servers

Load older messages


SenderMessageTime
11 Feb 2026
@alist:matrix.orgfnctr changed their profile picture.11:36:26
@alist:matrix.orgfnctr changed their profile picture.11:39:11
@alist:matrix.orgfnctr changed their profile picture.11:40:11
@alist:matrix.orgfnctr changed their profile picture.11:41:57
@alist:matrix.orgfnctr changed their profile picture.11:46:43
13 Feb 2026
@hoplophfeil:matrix.orghoplopf joined the room.10:19:51
@b:chreekat.netchreekatas a sanity check, if a tool was introduced that created a drv for every source file of every haskell dependency of your haskell package, that would be unreasonable, right? Way too many drvs?15:04:19
@maralorn:maralorn.demaralornNot necessarily. Probably? Eval times might be horrendous. But I wouldn't bet on that. The question is usually what this drvs do and for many usecases, like e.g. compiling the overhead per drv makes it very slow.15:09:47
@b:chreekat.netchreekatinterestin15:11:09
@b:chreekat.netchreekat* interesting15:11:12
@b:chreekat.netchreekatcontext is that i'm experimenting with using casa as a source for package sources. Right now, the tool fetches tree manifests and blobs from casa and assembles them into a package source tree that can be built in a later step15:12:04
@b:chreekat.netchreekatusing IFD it's unusable, but the goal is to try using dynamic derivations / rfc9215:12:38
@b:chreekat.netchreekat(pre-generation would be another option)15:13:27
@maralorn:maralorn.demaralornI have optimised our work CI by making on hlint/ormulo check derivation per file. Without caching it is a bit slower but once the store is populated the speedup is significant.15:14:01
@maralorn:maralorn.demaralorn * 15:14:28
@toonn:matrix.orgtoonn chreekat: Isn't that what haskell.nix does? 15:16:18
@b:chreekat.netchreekatit doesn't use casa as far as I know.15:21:33
@toonn:matrix.orgtoonn No, re drv per Cabal component. Though that's not exactly what you said, I suppose. 15:22:20
@maralorn:maralorn.demaralornPer Cabal component and per source file is a big difference15:23:14
@b:chreekat.netchreekatYeah, and ironically per-component builds aren't my goal right now. My main goals are to make a tool that lets stack.yaml(.lock) be the source of truth for a nix build, that is also fast. I guess using casa is an orthogonal goal, but it feels right because casa is, or could be, a better solution than the all-cabal-hashes repo15:25:07
@b:chreekat.netchreekatit was sort of the next generation of "better interface to hackage" that fp complete was experimenting with. stack uses it, but besides that it sort of got trapped in amber as fpco moved away from haskell15:25:59
@b:chreekat.netchreekatwoo, the ginormous IFD fetch of all sources finally finished, it's compling shit now15:37:12
@me:linj.techlinjI am also interested in dyn drv. Could you share some learning materials of it?16:06:15
@b:chreekat.netchreekatwell, i don't really know of any. I myself am building this experiment in hopes of learning something about it16:47:19
@b:chreekat.netchreekat confession: i am using claude. But I'm minimizing the blast damage by compartmentalizing the steps and checking carefully all the parts I do understand 16:48:52
@alexfmpe:matrix.orgalexfmpe
In reply to @b:chreekat.net
as a sanity check, if a tool was introduced that created a drv for every source file of every haskell dependency of your haskell package, that would be unreasonable, right? Way too many drvs?
https://github.com/obsidiansystems/sandstone
17:04:11
@me:linj.techlinj tip: there are slides in the slides branch 17:51:34
@perigord:matrix.orgPerigord changed their profile picture.19:11:38
@alex:tunstall.xyzAlex It shouldn't be, but I think this is mostly a question of how efficiently Nix can handle derivations.
I suspect that there is little effort put into making them low overhead, given how little of Nixpkgs creates such small derivations.
19:41:09
@alexfmpe:matrix.orgalexfmpe summon John Ericson 19:49:32

Show newer messages


Back to Room ListRoom Version: 6