Colmena - Public Room Timeline

	Colmena	299 Members
	A simple, stateless NixOS deployment tool - https://github.com/zhaofengli/colmena	101 Servers

Sender	Message	Time
17 Jun 2025
Zhaofeng Li	Admittedly it's not easy to do directly, and in this specific case I think `nixos-rebuild` used the evaluation cache whereas Colmena cannot (you can test the raw evaluation speed by changing a file or passing `--option eval-cache false` to nixos-rebuild).	15:45:17
Zhaofeng Li	I wrote up what Colmena does to evaluate a configuration here: https://github.com/zhaofengli/colmena/issues/235	15:45:22
Zhaofeng Li	(cc: Khalil Santana)	15:46:55
Khalil Santana	Thank you! I'll test this and answer back with results	15:48:04
Khalil Santana	That seems to get `nixos-rebuild --flake` performance closer to colmena's, but there's still a significant difference (if I'm reading the output of `zsh`s `time` correctly, that is). `colmena apply --on=andromeda --nix-option eval-cache false 9,84s user 5,36s system 41% cpu 36,341 total nixos-rebuild switch --flake .#andromeda --target-host --option eval-cache 7,88s user 1,11s system 58% cpu 15,299 total`	15:54:11
Khalil Santana	I was trying to setup profiling in nix using this[1] to figure out why colmena is slower, but didn't quite succeed (I think I got a -ENOSPC or something due to `/tmp/` as tmpfs or something). Do you think something like this would be useful to debug this performance behaviour? [1] - https://github.com/crabdancing/nix-flamegraph	15:59:54