| 29 Oct 2024 |
|  eva removed their profile picture. | 22:26:39 |
| eva set a profile picture. | 22:26:54 |
| 30 Oct 2024 |
|  @seapat:matrix.org left the room. | 07:49:55 |
| 2 Nov 2024 |
|  Mel joined the room. | 03:07:18 |
|  drownbes changed their display name from Artem Markov to drownbes. | 08:42:16 |
| 5 Nov 2024 |
|  @grossmap:in.tum.de left the room. | 14:15:59 |
| 6 Nov 2024 |
|  @peddie:matrix.org left the room. | 12:33:19 |
| 8 Nov 2024 |
|  @printfn:matrix.org left the room. | 06:13:24 |
 p14 | I know there was some interest in having a PGO/LTO/BOLT clang build, as well. Some notes on build reproduciblity when PGO is involved: https://discourse.llvm.org/t/pgo-profile-reproducibility/82861/6
TL;DR: For profiles it is not enough for the profiling mechanism to be deterministic and the workload to have a deterministic output; the workload must compute the output in a flow-control deterministic way. Clang unfortunately uses inodes in a hash map, which makes the profile not reproducible, so it's not currently possible to have a reproducible PGO clang build. (Unless you control the inode integers that clang sees during profiling, among other horrible details). | 11:41:38 |
| 12 Nov 2024 |
|  pfhuh joined the room. | 05:55:01 |
| 13 Nov 2024 |
|  inayet joined the room. | 22:16:32 |
| 15 Nov 2024 |
|  Diamond (it/she) changed their profile picture. | 23:00:53 |
| 17 Nov 2024 |
|  Orzklv joined the room. | 02:29:19 |
| 19 Nov 2024 |
| Diamond (it/she) changed their profile picture. | 21:15:40 |
| 20 Nov 2024 |
| inayet removed their profile picture. | 00:59:09 |
| 22 Nov 2024 |
|  Morgan (@numinit) joined the room. | 17:50:55 |
| 27 Nov 2024 |
|  @sky1e:mildlyfunctional.gay left the room. | 03:15:14 |
|  @meidam:matrix.org left the room. | 10:58:30 |
|  jopejoe1 [4094] changed their display name from jopejoe1 to jopejoe1 [4094]. | 18:17:52 |
| 28 Nov 2024 |
|  @honnip:matrix.org left the room. | 04:03:35 |
|  shawn8901 left the room. | 18:48:41 |
| shawn8901 joined the room. | 18:54:09 |
| 29 Nov 2024 |
| p14 | https://r13y.com/ is broken, giving an S3 bucket access error | 15:37:55 |
| p14 | On reproducible builds and -frandom-seed:
- Technically nixpkgs is abusing it.
- https://github.com/bitcoin/bitcoin/issues/2290 -> Concluded it's not needed anymore for reproducible builds in practice.
- https://github.com/NixOS/nixpkgs/issues/153793 -> Noted it is being misused; AND that it breaks CA builds causing a rebuild.
- https://discourse.llvm.org/t/what-is-frandom-seed-useful-for/83345 -> Noted it does nothing on LLVM.
I ponder if it can be simply dropped. Anyone got experience with that?
Does anyone know or have evidence of the lack of frandom-seed causing reproducibility issues on modern GCC? https://github.com/NixOS/nixpkgs/blob/master/pkgs/build-support/setup-hooks/reproducible-builds.sh
| 15:38:17 |
 raboof | In reply to @p14:matrix.org
https://r13y.com/ is broken, giving an S3 bucket access error where did you still find a reference to it? the new place is https://reproducible.nixos.org | 15:38:36 |
| p14 | Ah. Here: https://github.com/NixOS/nixpkgs/pull/102251#issuecomment-720133612 | 15:38:51 |
| p14 | So I guess a good threshold for determining whether frandom-seed is needed or not would be the minimal iso reproducibility? | 15:39:22 |
| p14 | Oof, rsync isn't deterministic on nixos-unstable @ 4633a7c72337 as it is. | 15:42:35 |
| p14 | error: derivation '/nix/store/gppvg32hwnf1h9dvf38mjwfrs74s12jz-rsync-3.3.0.drv' may not be deterministic: output '/nix/store/x850848v3xl4wxjqzc3q9jp7j6fbkh27-rsync-3.3.0' differs
| 15:42:50 |
| raboof | interesting, it reproduces for me. could you diffoscope it and file an issue (https://github.com/NixOS/nixpkgs/issues/new?assignees=&labels=0.kind%3A+enhancement%2C6.topic%3A+reproducible+builds&projects=&template=unreproducible_package.md&title=)? | 15:45:33 |
