| 7 Feb 2025 |
 bryan | Yeah (`mod` 8) was broken by a faulty optimization implementation, and (more interesting imo) the tests apparently should have caught it but didn't | 16:33:12 |
|  terrorjack joined the room. | 22:29:59 |
| 8 Feb 2025 |
 sterni (he/him) | Got my haskell-packages.nix refactor done and also documented https://github.com/NixOS/nixpkgs/pull/378063 | 19:06:26 |
| 7 Feb 2025 |
|  terrorjack left the room. | 22:31:16 |
| 8 Feb 2025 |
| terrorjack set a profile picture. | 02:24:30 |
| terrorjack removed their profile picture. | 02:25:05 |
| 9 Feb 2025 |
 Tristan Ross | Is there a way we can get GHC to bootstrap without LLVM 12 on aarch64-darwin? Or is it strictly LLVM 12. (This was from a convo in !kxOJEqURGkuOHTRRQB:matrix.org) | 20:54:50 |
 maralorn | I think that depends on the GHC version. Newer versions have a native backend for aarch64-darwin I think. (And would also be compatible with a newer LLVM.) | 21:42:51 |
| Tristan Ross | In reply to @maralorn:maralorn.de
I think that depends on the GHC version. Newer versions have a native backend for aarch64-darwin I think. (And would also be compatible with a newer LLVM.) Ok because we need to figure something out since LLVM 12 is going away in 25.05. | 21:45:05 |
| maralorn | Well my opinion would be that we drop support for combinations which we can’t support. But that is for sterni to decide. | 21:50:17 |
| sterni (he/him) | Why? | 21:50:54 |
| Tristan Ross | In reply to @sternenseemann:systemli.org
Why? Because we have 8 versions and LLVM 20 is releasing soon. | 21:51:34 |
| sterni (he/him) | It seems to me that removing LLVM 13 and 14 are more interesting immediate goals since it's easier by comparison (though cling does seem to have a hard dependency on LLVM 13). | 21:54:07 |
| Tristan Ross | We're the only distro with LLVM 12 | 21:51:57 |
| Tristan Ross | Not even Debian has LLVM 12 | 21:52:13 |
| Tristan Ross | In reply to @sternenseemann:systemli.org
It seems to me that removing LLVM 13 and 14 are more interesting immediate goals since it's easier by comparison (though cling does seem to have a hard dependency on LLVM 13). Afaict, there's more things depending on more newer versions. | 21:54:54 |
| Tristan Ross | Plus we've been discussing this for like a year but haven't really done much. LLVM 12 has been EOL for 4 years as well. | 21:56:09 |
| 10 Feb 2025 |
 linj | In reply to @rosscomputerguy:matrix.org
We're the only distro with LLVM 12 guix has 12 and many older ones such as 3.5.2. Not saying that is better, though. https://packages.guix.gnu.org/search/?query=llvm | 01:51:41 |
| linj | there are many other distros like guix https://repology.org/project/llvm/versions | 01:54:33 |
| Tristan Ross | In reply to @me:linj.tech
guix has 12 and many older ones such as 3.5.2. Not saying that is better, though. https://packages.guix.gnu.org/search/?query=llvm Oh, I didn't know that. | 01:59:50 |
| Tristan Ross | In reply to @me:linj.tech
there are many other distros like guix https://repology.org/project/llvm/versions There's literally hundreds of distro's but if we're able to, I don't see the reason to not drop it. How many potential security issues are there in older LLVM versions which have been patched? | 02:01:02 |
 emily | I think @maralorn:maralorn.de's survey would give useful data here | 05:43:13 |
| emily | (but also given LLVM bitcode compatibility guarantees I still see no reason we couldn't unpin LLVM for older GHCs) | 05:43:35 |
| Tristan Ross | Yeah, I remember bringing that up or seeing that brought up a few times here since at least August. | 05:49:57 |
| maralorn | In reply to @emilazy:matrix.org
I think @maralorn:maralorn.de's survey would give useful data here I am sorry, but I lost steam on that one after my initial push for a deprecation policy got rejected. I know I said I'd do that survey but then certain unforeseen non-computer things happened which absorbed a too much of my spare time. | 08:02:21 |
| sterni (he/him) | lol the github UI is having a complete meltdown, it now claims I force pushed haskell-updates?! | 14:21:55 |
| sterni (he/him) | emily: We don't really need a survey; just look at nixpkgs: LLVM 12 is used by, among other things, GHC versions; those GHC versions are also used e.g. by elm related stuff | 14:23:05 |
| sterni (he/him) | removing that is just a lot of churn figuring out whether packages can be upgraded etc. but you have to start from the bottom and work your way upwards | 14:23:41 |
| sterni (he/him) | GHC does generate notoriously weird LLVM bitcode, occasionally running into the limits of llc/optc in strange ways. As a consequence, I don't think it is safe to just assume that older GHC versions will just work with newer LLVM versions, especially since it is hard to gain confidence from our CI since the LLVM backend stuff is not well covered anymore for the affected GHC versions. I'm not willing to bump GHC before we have verified that GHC did not have to make any changes to the backend to accomodate the newer LLVM versions. Unfortunately, I'm busy with other things, but happy to do that at some point. | 14:26:07 |
| sterni (he/him) | I am also open to removing 8.10-9.2, but as things stand there are some major challenges associated with it. I can write up the state of that in more detail on the LLVM removal issue or maybe a separate issue? | 14:30:02 |
