| 29 Mar 2022 |
 toonn | Does Darwin come with xz? It didn't use to. | 14:01:31 |
| toonn | Even then I don't think it's a necessary prerequisite. | 14:01:51 |
 tpw_rules | how is it not? how does that flow work? | 14:09:14 |
| tpw_rules | also maybe it doesn't, it looks like i have it installed via homebrew | 14:09:36 |
 atemu12 | xz is not on Darwin system either. | 14:19:01 |
| atemu12 | In reply to @tpw_rules:matrix.org
but otoh i think xz is non-reproducible in multithreaded mode I think this is the most important of any of the compressor up- and downside mentioned yet. Nondeterminism due to compression is not something we want I think | 14:20:03 |
| atemu12 | * xz is not on my Darwin system either. | 14:20:59 |
| toonn | tpw_rules: It doesn't really matter because cpio and bzip2 are currently kinda also part of the bootstrap tarball, separately but still. | 14:24:12 |
| toonn | tpw_rules: https://github.com/NixOS/nixpkgs/blob/master/pkgs/stdenv/darwin/default.nix#L18-L20= | 14:25:10 |
| tpw_rules | ok. i don't know exactly how the bootstrap extraction works. | 16:26:38 |
| tpw_rules | zstd and i think lzip are both reproducible. but i think neither guarantee it if the compressor version changes | 16:27:16 |
| 30 Mar 2022 |
|  dtz joined the room. | 02:31:56 |
|  @etrigan63:matrix.org left the room. | 03:09:45 |
| 31 Mar 2022 |
| toonn | Done some initial "benchmarks", nix-build --check always says it's not reproducible with any format. So I guess the source material isn't reproducible yet. Is it still worth making the change from cpio -> tar then? | 13:14:38 |
| tpw_rules | for the macos bootstrap? are you sure it's not cpio including inodes or bzip2 including a timestamp? that would fail reproducibility every time | 17:17:45 |
 wamserma | cpio can also include timestamps, device names and link count :) diffoscoping might help there | 17:19:21 |
| toonn | But tar + lzip/zstd is also failing to reproduce. | 17:35:20 |
| tpw_rules | oh, i misinterpreted what you meant. then yeah i would throw two builds into diffoscope and see what happens | 17:36:26 |
| tpw_rules | did you set all the files to the same date? | 17:37:29 |
| tpw_rules | https://github.com/NixOS/nixpkgs/blob/9cd1fa9bcef3b578a732a391436aad804e03e3ca/pkgs/build-support/kernel/make-initrd.sh#L42 that sets them all to 1 second after 1970 for instance | 17:40:16 |
| toonn | I did not do any such processing, no. | 18:10:19 |
| tpw_rules | ok. i might try to fiddle with it myself if you would like. i just didn't want to send a PR to touch something so fundamental without clearance from someone like you | 19:50:15 |
| toonn | It's fine. | 20:11:23 |
| tpw_rules | https://github.com/NixOS/nixpkgs/blob/8465654f6ab72bb765e584cbb45674d4fd6d8da1/pkgs/stdenv/linux/make-bootstrap-tools.nix#L198 | 20:12:42 |
| toonn | Might be nice to synchronize merging with something that also requires a bootstrap tools rebuild, since it's not a very urgent thing. | 20:13:11 |
| toonn | I'll give that a shot tomorrow. | 20:15:39 |
| tpw_rules | cool, thank you | 20:16:28 |
| tpw_rules | (is your icon meant to be Marvin from h2g2) | 20:16:52 |
| toonn | No, because of copyright reasons : > | 20:17:56 |
| 1 Apr 2022 |
| toonn | tpw_rules: Looks like it was the times making it non-reproducible. | 17:46:52 |
