| 29 Sep 2022 |
 tpw_rules | is there some sort of talk announcement for this? i joined but just want some context | 19:25:35 |
 fzakaria | last minute -- sorry | 19:26:42 |
| fzakaria | it was : https://ospo.ucsc.edu/post/20220823/ | 19:26:47 |
| fzakaria | or
https://docs.google.com/document/u/1/d/e/2PACX-1vQin8rKcMZhWwi31e2Djbbvgo8uAWexyRixqQHUgEpmeXGn5As465yKhZl8IEpvuBmDfzly9ybxo5w8/pub | 19:27:15 |
| fzakaria | we are on the tail end now | 19:27:33 |
| tpw_rules | ah, you are presenting? | 19:27:51 |
| tpw_rules | i have used nix on hpc before but more just as a curiosity | 19:28:53 |
| tpw_rules | but demonstrating that it's practical to use without administrator collaboration | 19:31:56 |
| tpw_rules | oh that's what you meant by tail end | 19:34:26 |
| tpw_rules | how did it go? is there a recording? | 19:34:33 |
| tpw_rules | * oh that's what you meant by tail end. i misread your message's time. | 19:34:56 |
|  @rimuru:gentoo.chat changed their profile picture. | 21:30:33 |
| 30 Sep 2022 |
|  chreekat changed their profile picture. | 12:16:42 |
|  louib joined the room. | 13:04:32 |
| fzakaria | i think there will be a recording published + slides | 16:04:46 |
| fzakaria | the part by Todd Gamblin on their use of sat solving for version picking is very cool | 16:05:01 |
| fzakaria | in Spack they allow different versions of the dag, and they use sat solving to come up with correct builds or even minimal rebuilds according to what's in the cache already | 16:05:24 |
| fzakaria | https://spack.io | 16:05:31 |
| tpw_rules | how does it constrain things? version numbers? | 16:55:30 |
| tpw_rules | * how does it constrain things? version numbers? i assume that's what "version picking" means | 16:58:55 |
 tnias | you can provide constrains like what packages you are interested in and (optionally) their version numbers, compiler flags, etc.
then there is a sat solver (they call it concretizer) that provides a solution to the constrains. This solution is saved as a *.lock file. From a lock file you can reproduce the environment.
packages can also provide their own constraints. as in: "version x of this package needs gcc >= 9"
| 17:29:27 |
| tnias | (at least that is my understanding of the talk) | 17:30:56 |
|  @0b11:matrix.org removed their display name 0x53. | 17:33:15 |
| @0b11:matrix.org left the room. | 17:33:26 |
 afontain | how is that different from what debian does ? | 17:38:18 |
| afontain | someone had fun solving sudoku puzzle with debian packages constraints | 17:38:51 |
|  0xMRTT [envs.net] joined the room. | 18:43:32 |
| fzakaria | let me share his slide deck | 22:00:13 |
| fzakaria | Download spack-ucsc-ospo22.pdf | 22:00:40 |
| fzakaria | Spack is like Nix; it's different than debian since it can also do source base compilation | 22:00:47 |
