| 19 Aug 2023 |
 Zhaofeng Li | Nix works fundamentally differently from other package managers. The package versions are decided when you evaluate the expression, and for Colmena everything is evaluated locally on the host you are deploying from | 19:31:33 |
| Zhaofeng Li | so with channels, it will follow whatever you have on the machine running colmena | 19:31:59 |
 @khalilsantana:matrix.org | Pretty neat! So I guess I don't need to do anything special, just run an apply once in a while | 19:33:55 |
| @khalilsantana:matrix.org | (I've seen there's an auto-upgrade option in nixos itself, but I'd rather have more control) | 19:34:29 |
| Zhaofeng Li | As a more concrete demonstration, run nix-build '<nixpkgs>' -A hello and you will get a path. This path is unique to this specific version of hello, tied to everything that it depends on:
$ nix-store -qR /nix/store/qi2wm8z1m8c8x164ki6r4fbpfl7is735-hello-2.12.1
/nix/store/2y9zl8ky5ac28ali6ly1zfz11d4fq48b-xgcc-12.3.0-libgcc
/nix/store/ic9wnagwh22yhqh3lcdlnv5m178w6f0f-libunistring-1.1
/nix/store/a9mxddm4a5p4kp84vys4n2nrmwqgk7kr-libidn2-2.3.4
/nix/store/1x4ijm9r1a88qk7zcmbbfza324gx1aac-glibc-2.37-8
/nix/store/qi2wm8z1m8c8x164ki6r4fbpfl7is735-hello-2.12.1
| 19:37:53 |
 Wanja Hentze | In reply to @khalilsantana:matrix.org
(I've seen there's an auto-upgrade option in nixos itself, but I'd rather have more control) yes, I don't think the auto-upgrade feature will work well at all with colmena | 19:40:23 |
| Zhaofeng Li | Say later there's a vulnerability that requires you to patch glibc-2.37-8. Nothing changes about this specific hello - It will still use the same exact unpatched glibc-2.37-8 as you originally built it. Therefore there aren't really upgrades - Any change results in a totally different package in a different path | 19:41:45 |
| Zhaofeng Li | Sorry if this is too verbose - I wanted to clear some things up, as the questions about "upgrades" and "adding new packages" suggested some misunderstanding | 19:43:04 |
| @khalilsantana:matrix.org | Understood. I like the in-depth explanations since I'm pretty new to nix, so I'm still getting my mind wrapped around it. It certainly doesn't help that the nix pkg in my distro was/is busted | 19:45:57 |
