| 21 Jan 2026 |
 dutchie | I guess I need to point it at a subdir or something | 14:35:08 |
| dutchie | hmm I can just overrideCabal { doCheck = false; } | 14:44:02 |
| dutchie | or dontCheck actually | 14:53:40 |
| 22 Jan 2026 |
|  Supreme Allied Commander Mayhem, Lord of the Nine Stars changed their display name from Grand Warden Mayhem, Punisher of Deer to Supreme Allied Commander Mayhem, Lord of the Nine Stars. | 01:27:17 |
|  LordMZTE joined the room. | 16:12:54 |
| LordMZTE | It seems like GHCJS isn't in nixpkgs. Does anyone know a good way to set it up in a dev shell?
| 16:14:23 |
 Acid Bong | twas removed: https://github.com/NixOS/nixpkgs/pull/422342 | 16:15:05 |
| Acid Bong | you can still save that recipe and use it locally tho | 16:16:12 |
| LordMZTE | I see. Surely someone must have taken over maintaining this out of tree, right?
| 16:17:10 |
 emily | AIUI the newer GHCJS is a native GHC backend and is accessible with pkgsCross.ghcjs or something | 16:22:15 |
| emily | it was the old GHCJS that was removed | 16:22:19 |
| Acid Bong | oh | 16:22:26 |
| Acid Bong | i can't find ghcjs in the search | 16:22:38 |
| emily | it's a platform, not a package | 16:31:38 |
 maralorn | Yes, the new js backend is supported in nixpkgs. | 16:40:04 |
 alexfmpe | shellFor doesn't work for cross AFAICT, but you can whip something up manually
here'ss one example: https://github.com/bfeitknecht/impli/pull/6/files | 17:09:00 |
| alexfmpe | that reminds me, I haven't checked pkgsCross.ghcjs status with 9.14 | 17:09:46 |
| alexfmpe | nix-build here builds everything with nix, nix-shell grabs the tools from nixpkgs then uses cabal-install for the rest, wrapping it so it uses js backend | 17:12:33 |
| alexfmpe | shellFor, were it to work here, would build all the deps with nix, so cabal-install/ghci(d) would only be used for your own project | 17:13:07 |
| LordMZTE | Thanks!
| 18:02:56 |
|  @wolfgangwalther:matrix.org left the room. | 19:17:01 |
| 23 Jan 2026 |
| LordMZTE | I'm using shellFor for a devshell for my Haskell project and I want to debug a library I'm pulling in (via cabal2nix). For this, GHCi needs to run the library in interpreted mode, but using cabal repl, it's used in compiled mode and I cannot set breakpoints in it. Is there a way to also get the source code of libraries in a dev shell?
| 13:50:03 |
| maralorn | The best I can think of is checking that library out in a (sub-)folder and adapting your cabal.project file to use it. | 13:57:19 |
| maralorn | I mean I guess you can try to get nix to give you a store path of the source and try to point your cabal.project file at that, but I don’t know if it works, am not aware of any tooling specific for this und wouldn’t recommend it. | 13:58:44 |
| LordMZTE | Alright. Sort of unfortunate :P
| 14:38:10 |
| alexfmpe | I think that if you add both your package and that library to the packages field of shellFor, then when you run cabal repl, it will grab all the intermediate deps and throw into ghci as well.
Might need to enable multi-repl | 16:19:31 |
| alexfmpe | Well actually I'm not sure if shellFor handles the sandwhich situation right | 16:20:41 |
| alexfmpe | If it doesn't, I expect it can be fixed. I've some shitty nix that does that for obelisk projects | 16:21:14 |
| alexfmpe | Context: https://www.well-typed.com/blog/2024/07/hls-multi/#the-need-for-cabal-install-3.12 | 16:21:51 |
| Acid Bong | note that cabal-install must also be in the same Haskell closure to be able to see other libs | 16:52:46 |
