| 25 Sep 2025 |
 bglgwyng | I suppose that we don't have force generic-builder to use a specific package with id | 12:00:43 |
| bglgwyng | * I suppose that we don't have a way to force generic-builder to use a specific package with id | 12:01:26 |
 maralorn | I think Setup.hs has a mode to do that. But we currently don’t use it in the generic-builder and it might be non trivial. | 12:02:16 |
| bglgwyng | Thanks! but, wht does 'non trivial' mean here? | 12:03:04 |
| maralorn | It means, that it could be that a) if you do this you need to specify the hashes of all dependencies (and I think in that mode you disable bound checking completely) and b) it might be hard to figure out the correct hashes to inject there. Basically we would be reimplementing logic which we currently rely on from Setup.hs. | 12:12:26 |
| maralorn | Does not sound insurmantable. | 12:12:47 |
| maralorn | It might even be feasible do improve the generic-builder to enforce the usage of passed in overrides more reliably in general. That could be cool. | 12:13:28 |
| maralorn | * Does not sound insurmountable. | 12:13:43 |
 sterni (he/him) | https://cabal.readthedocs.io/en/stable/setup-commands.html#cmdoption-runhaskell-Setup.hs-configure-dependency | 15:26:31 |
| maralorn | Ah, nice. | 15:27:13 |
| maralorn | That’s less complicated than what I had in mind. | 15:27:28 |
| sterni (he/him) | I think the problem here is figuring out the right installed package identifier. I believe how this is computed is pretty much internal to Cabal | 15:27:35 |
| maralorn | You can most certainly not know it a nix eval time. So you will probably need to do some finding through build inputs. | 15:28:33 |
| 26 Sep 2025 |
| bglgwyng | Maybe I'm doing something hacky so I want to convince my self;
did the same thing happen when we tried to override a pakcage with the same version in haskell.packages and different transitive dependencies? | 03:28:54 |
| bglgwyng | yes this worked | 03:41:00 |
|  @aspendowntime:matrix.org removed their profile picture. | 05:46:41 |
| @aspendowntime:matrix.org removed their display name Eden (they/it/she). | 05:47:00 |
| @aspendowntime:matrix.org left the room. | 05:47:41 |
| bglgwyng | Where is pkgsHostTarget passed from?
https://github.com/NixOS/nixpkgs/blob/5364a5ff96df5c2e3b1048914f90fc39530087c2/pkgs/development/haskell-modules/generic-builder.nix#L641 | 09:28:48 |
| sterni (he/him) | pkgs/stdenv/generic/setup.sh | 09:51:35 |
| sterni (he/him) | yes this also happens in that case, hence you need to overrideScope | 09:52:08 |
| maralorn | A recent ghc version started embedding links to the ghc error index via terminal control codes. | 14:14:39 |
| maralorn | That doesn’t seem to work in nix logs. | 14:15:07 |
| maralorn | Does anyone know how that can be fixed? | 14:15:23 |
| maralorn | If not maybe we should deactivate/strip it? | 14:15:41 |
| maralorn | Looks like that for me:
<no location info>: warning: [8;;https://errors.haskell.org/messages/GHC-42258GHC-422588;;] [-Wunused-packages]
| 14:16:36 |
 Alex | My guess is that [8;; is some kind of terminal escape code.
Although undesirable, does disabling colours work? | 15:03:59 |
 Teo (he/him) | A quick glance at the GHC codebase points me to GHC.Types.Errors where it seems like this is always emitted irrespective of whether you are in a fancy terminal. We probably shouldn't do that | 15:06:29 |
| Teo (he/him) | Ah wait no it is a setting | 15:06:50 |
| Teo (he/him) | yeah it determines if your terminal supports colours and only uses it in that case. And you can disable it with fprint-error-index-links=never | 15:08:23 |
