 | Nix Hackers | 876 Members |
| For people hacking on the Nix package manager itself | 188 Servers |
| Nix Hackers | 876 Members |
| For people hacking on the Nix package manager itself | 188 Servers |
| Sender | Message | Time |
|---|---|---|
| 12 Sep 2025 | ||
 jaen | So basically what you'd like me to do is to take https://github.com/NixOS/experimental-nix-installer and rebase it on top of recent upstream (any particular commit, last before they dropped support for upstream nix maybe)? | 17:36:08 |
| 13 Sep 2025 | ||
 ysndr joined the room. | 01:28:20 | |
 fzakaria | hi everyone | 20:45:30 |
 oak 🏳️🌈♥️ changed their profile picture. | 09:46:11 | |
 Sergei Zimmerman (xokdvium) | Honestly there's also only things that you can find out at scale. For one, memory usage and value representation is very important. It's not the interpreter or parser that's the bottleneck | 20:47:36 |
| Sergei Zimmerman (xokdvium) | Experimenting with efficient sharing of immutable values would be great. I have some thoughts on this that might manifest into something tangible soon | 20:48:42 |
 magic_rb | im currently still trying to wrap my head around the STG | 20:49:01 |
| Sergei Zimmerman (xokdvium) | Also the plus/minus implementation is a bit more complex than this: https://git.redalder.org/magic_rb/nix-stg/commit/04839e29e51a3b237359d0e95239e2b6960334ff. Like consider the following: | 20:53:18 |
 puck | i mean; the nix language is a bunch of scope resolving and then a bunch of primop calls, there's not much inbetween | 20:54:14 |
| puck | the nix language without e.g. derivation is ... kinda hard to use | 20:55:05 |
| puck | i once experimented by taking the nix source code and taking out everything that isn't the expression interpreter; very little was left. just a handful of primops; i didn't even have import because it depended on the FS | 20:55:40 |
| puck | comparing with e.g. https://nix-re.pl/ which translates everything to a primop call (a + b -> __add a b; a.b.c or d -> __selectOr a [ "b" "c" ] d) | 20:56:27 |
| puck | all this to say i don't think there's much of a subset of Nix that would let you reasonably test performance; the only real-world performance test i can think of is "how well can you evaluate nixpkgs"; which requires .. well, everything | 21:00:59 |
| magic_rb | right, okay, point taken, ig ill have to implement enough to eval nixpkgs to actually get any data | 21:10:14 |
| magic_rb | ... | 21:10:15 |
| magic_rb | well, im not even at a functional VM so uh, thats ways off, currently trying to wrap my head around the STG still | 21:10:36 |
| magic_rb | okay, i have no clue what im doing, anyone know the STG and can help me find the bug? or anyone up for a fun pairing? I'm pretty sure im folling the paper to the letter but its being weird, i suspect a miscompilation from Nix -> STG, cause the STG VM is behaving exactly as the paper says | 21:32:15 |
| jaen | Slowly working on installer rebase and need an opinion — I have some tests that are failing because it assumes existence of a default profile that has nix in it, cf:https://github.com/DeterminateSystems/nix-installer/blob/8a7bb095d93ada552d20d2f22ffd9f1668f8e394/src/profile/nixenv/tests.rs#L135-L136 https://github.com/DeterminateSystems/nix-installer/blob/8a7bb095d93ada552d20d2f22ffd9f1668f8e394/src/profile/nixenv/mod.rs#L98 It is not the case on my system, it links into per-user/root/profile which does not exist (the folder only has channels there. And I'm wondering if it's my NixOS setup that's wrong or is detsys assuming something that's not really true? | 21:59:15 |
| 14 Sep 2025 | ||
 Emma [it/its] joined the room. | 08:32:48 | |
 @azharmomin:kde.org joined the room. | 16:22:28 | |
| @azharmomin:kde.org left the room. | 16:37:42 | |
 @xworld21:matrix.org left the room. | 18:37:24 | |
| 15 Sep 2025 | ||
| Sergei Zimmerman (xokdvium) | Btw here's the manifistation of this fever dream of mine: https://github.com/NixOS/nix/pull/13987 | 00:16:54 |
| 16 Sep 2025 | ||
 getchoo | i think i have a decent solution here: https://github.com/getchoo-contrib/nix/tree/getchoo/dogfood-experimental-installer it currently grabs the artifacts the 0.27.0, but it wouldn't be too hard to extend to fetch from the main branch builds (if they actually uploaded their artifacts)dogfooding even works as well! ...but i did come across an interesting problem | 04:18:02 |
| getchoo | when dogfooding is an enabled with this experimental installer option, you'll end up with an 4: Failed to execute command HOME="/root" "/nix/store/dkmylx2wyz9i6ycbmr07lpv15mph0d7y-nix-main-2.32.0pre/bin/nix-store" "--load-db"`` errori traced it back to this pretty naive snippet of code that basically just takes the first path in the store matching nix-* and runs it, with no checks for if /bin/nix-store actually exists https://github.com/NixOS/experimental-nix-installer/blob/20be610e1f29c8a127146da67ed56f879b173ac6/src/action/base/setup_default_profile.rs#L55-L70 | 04:19:47 |
| getchoo | this worked before the component split in 2.29 since there would only be one main nix store path at this point, but now it matches the nix-main store path first, which doesn't a bin dir or any of the nix binaries | 04:21:02 |
| getchoo | i figured this was something probably fixed in an update upstream and i'd need to wait on a rebase, but the code there actually remains entirely the same https://github.com/DeterminateSystems/nix-installer/blob/8a7bb095d93ada552d20d2f22ffd9f1668f8e394/src/action/base/setup_default_profile.rs#L56-L69 | 04:22:07 |
| getchoo | i think this might only work because the hash part of the release nix store path happens to be sorted before the other components, while it isn't in the pre-release tarball from the artifacts i'm pushing into this lol | 04:33:40 |
| getchoo | * when dogfooding is enabled with this experimental installer option, you'll end up with an 4: Failed to execute command HOME="/root" "/nix/store/dkmylx2wyz9i6ycbmr07lpv15mph0d7y-nix-main-2.32.0pre/bin/nix-store" "--load-db"`` errori traced it back to this pretty naive snippet of code that basically just takes the first path in the store matching nix-* and runs it, with no checks for if /bin/nix-store actually exists https://github.com/NixOS/experimental-nix-installer/blob/20be610e1f29c8a127146da67ed56f879b173ac6/src/action/base/setup_default_profile.rs#L55-L70 | 04:33:57 |
| getchoo | * when dogfooding is enabled with this experimental installer option, you'll end up with an 4: Failed to execute command \HOME="/root" "/nix/store/dkmylx2wyz9i6ycbmr07lpv15mph0d7y-nix-main-2.32.0pre/bin/nix-store" "--load-db"`error i traced it back to this pretty naive snippet of code that basically just takes the first path in the store matchingnix-*and runs it, with no checks for if/bin/nix-store` actually exists https://github.com/NixOS/experimental-nix-installer/blob/20be610e1f29c8a127146da67ed56f879b173ac6/src/action/base/setup_default_profile.rs#L55-L70 | 04:34:15 |