| 7 Dec 2025 |
|  Robert Evans set a profile picture. | 19:02:47 |
 iopq | <<loop>> | 19:40:04 |
 sterni | then that issue is completely unrelated to Nixpkgs, given that that's a Haskell RTS error?! | 21:55:41 |
| sterni | https://www.stackage.org/diff/lts-24.23/nightly-2025-12-07 | 21:57:46 |
| 9 Dec 2025 |
|  andromeda joined the room. | 04:42:52 |
| andromeda | hallo | 04:45:22 |
| andromeda | does anyone have a Nix flake that builds a package for Hackage without using Cabal? Like without having the 'redundancy' of a Nix build specification in the flake and a Cabal specification in the .cabal file? | 04:46:23 |
 Alex | In reply to @andromeda:tchncs.de
does anyone have a Nix flake that builds a package for Hackage without using Cabal? Like without having the 'redundancy' of a Nix build specification in the flake and a Cabal specification in the .cabal file?
builds a package for Hackage without using Cabal
AFAIK Hackage always requires a Cabal description by design. | 04:47:50 |
| andromeda | hmm I could use the metadata defined in the flake to create a .cabal at build time for reproducibility | 05:02:12 |
| andromeda | oder? | 05:02:28 |
| andromeda | 
Download 20251209_06h35m40s_grim.png | 05:35:58 |
| andromeda | goodness what is Cabal's problem /j | 05:36:10 |
|  terrorist :: Feline joined the room. | 06:47:19 |
 MangoIV | No and it’s both a bad idea and it’s misguided.
- nixpkgs haskell support (and Haskell.nix) uses cabal anyway so you don’t get around it
- nobody except nix users will be able to build your package
- nix flakes are even worse on that sense
- please don’t upload things to hackage that people cannot build for that reason.
My tip is to use cabal as the source of truth.
| 08:42:50 |
| andromeda | so I'm thinking that I a) use ghcWithPackages to get libraries through Nix b) use cabal-install nix package for building and c) make build scripts .sh files or something so someone without nix will have no trouble building it. Does that sound workable? | 08:58:10 |
 maralorn | @andromeda:tchncs.de I don't understand what you are trying to achieve. Writing a Haskell package builder for nix is a major undertaking why not use one of the existing ones? | 09:06:16 |
| maralorn | Ah, I was misunderstanding. | 09:07:31 |
| maralorn | But I am still unsure what you are trying to achieve. | 09:09:04 |
| andromeda | I want to be able to nix run .#debug to run my debug build, .#release for the release build, and .#docs to build Haddock into $out/docs. I currently have this implemented, but, as previously mentioned, people without Nix can't build it. By using Cabal as the actual build system and calling it from build scripts, I can use Nix as just a package manager which calls those same build scripts. Rather than using Nix as the package manager and build system like prior | 09:12:56 |
| andromeda | can I see an example of like a well-done flake for a haskell package? | 09:13:43 |
| andromeda | so 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 | Ah, I see | 09:16:24 |
| andromeda | Nix's flexibility is a blessing and a curse xD | 09:16:49 |
| maralorn | My best flake is probably this one others might have cleaner ones: https://github.com/maralorn/nix-output-monitor/blob/main/flake.nix | 09:19:33 |
| maralorn | But I am not saying that everything in there is recommended for every project | 09:20:20 |
| andromeda | yo you write nom!? Awesome! I use it every day | 09:20:38 |
| maralorn | Anyway the spirit of nixpkgs is generally to reuse language specific build instructions instead of dodging them. | 09:22:33 |
| maralorn | This is imo not a failure to separate concerns | 09:22:51 |
| maralorn | nix does not know anything about Haskell or cabal | 09:23:14 |
| maralorn | But 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 |
