| 15 Sep 2025 |
 emily | we talked about this recently and I suggested a package set would be interesting for exploring future GHC bootstrap | 12:26:04 |
| emily | especially since we can have MicroHs bootstrap from hugs | 12:26:15 |
| emily | @alex:tunstall.xyz has that Nixified apparently | 12:26:28 |
 sterni (he/him) | should be testu-01, not testu01 from your example? | 12:26:50 |
| sterni (he/him) | bglgwyng: override allows you to use the result of callPackage and call the underlying lambda again with different argument, completely recomputing the value: https://github.com/NixOS/nixpkgs/blob/f501ecd2f4b1b8c4f43fee3f1d5cf3e758c2e166/lib/customisation.nix#L116-L208 | 12:28:43 |
| sterni (he/him) | You can of course not change the underlying function. I'm not entirely sure what you are trying to do. | 12:29:10 |
 Alex | Sure, I can contribute a package set later this week.
There might be a fair bit of flux from frequent upstream changes, but I doubt that'll be much of an issue. | 12:53:41 |
| emily | why does it need its own Cabal btw? | 12:56:19 |
| emily | is real Cabal not flexible enough? can't build with MicroHs? | 12:56:28 |
 chreekat | Yeah it relies on many language extensions that Lennart doesn't plan to support | 12:58:13 |
| emily | this is my fear with the GHC bootstrapping plan... | 13:00:07 |
| emily | either Lennart bends, Cabal/GHC maintainers do, or it's a fork situation | 13:00:32 |
 MangoIV | I think the one that Lennart won’t support is TH and that can’t be used in GHC either | 13:08:07 |
| MangoIV | Oh well… I guess if it’s used in boot libraries might still be an issue huh | 13:09:17 |
 Teo (he/him) | TH proper isn't used in boot libraries only TemplateHaskellQuotes, which means you don't have to worry about the tricky thing which is running splices | 13:11:13 |
| Teo (he/him) | In the long term, idk if GHC will continue to not use TH. GHC currently uses Generics to derive some of its typeclass instances and it leads to horribly slow compilation. TH would be one way to handle that in a better way. We can't currently use it, but that should be unblocked soon. I think the alternatives would be making Generics not slow, or a new way to derive instances | 13:12:58 |
| emily | IIRC he said no plans for implicit params or magic hash, which sound like things GHC would plausibly use | 13:13:01 |
