In reply to @buckley310:matrix.org
I just disable the binary caches in the configs of machines with no internet. Less typing

In reply to @winterqt:nixos.dev
So when using buildOnTarget, what decides if the drv should be built and copied on the host or built on the target? I know most do the latter, but things such as a source folder (from a flake input) have definitely gotten copied before, so...

When I run colmena build --on some-host, colmena will be stuck in the "Evaluating" step and seemingly never ends. When I run colmena build --on some-host -v (note the added -v argument), the same build continues normally and finishes within one minute.

Example output:

# Time 00:25:20 
$ colmena build --on some-host
warning: Git tree '/path/to/my/nixos-config' is dirty
[INFO ] Using flake: git+file:///path/to/my/nixos-config
[INFO ] Enumerating nodes...
warning: Git tree '/path/to/my/nixos-config' is dirty
warning: Git tree '/path/to/my/nixos-config' is dirty
warning: Git tree '/path/to/my/nixos-config' is dirty
[INFO ] Selected 1 out of 13 hosts.
                🕓 54s 1 running
# I pressed Ctrl-C after ~1min, but it will run forever if I didn't do that

# Time 00:26:19
$ colmena build --on some-host -v
warning: Git tree '/path/to/my/nixos-config' is dirty
[INFO ] Using flake: git+file:///path/to/my/nixos-config
[INFO ] Enumerating nodes...
warning: Git tree '/path/to/my/nixos-config' is dirty
warning: Git tree '/path/to/my/nixos-config' is dirty
warning: Git tree '/path/to/my/nixos-config' is dirty
[INFO ] Selected 1 out of 13 hosts.
some-host | Evaluating some-host
some-host | warning: Git tree '/path/to/my/nixos-config' is dirty
some-host | Evaluated some-host
some-host | Building some-host
some-host | /nix/store/xl1n3k4vbd8aa20kgs6nx10wyyzmbiij-nixos-system-some-host-22.05pre-git
some-host | Built "/nix/store/xl1n3k4vbd8aa20kgs6nx10wyyzmbiij-nixos-system-some-host-22.05pre-git"
          | All done!
# Time 00:26:36, the same job is done in 20 seconds

When colmena is stuck, it seems to be waiting for a defunct nix-store process:

$ ps -aux
# ...
lantian   811648  0.1  0.0 1225260 6016 pts/1    S<l+ 00:25   0:00 colmena build --on some-host
lantian   847160  0.0  0.0      0     0 pts/1    Z<+  00:25   0:00 [nix-store] <defunct>

Bisect shows this issue is introduced in https://github.com/zhaofengli/colmena/commit/26b2203da9a8a0f7913c61de3343430da66579b5.

I'm on latest nixos-unstable, and here's my nix-info report:

 - system: `"x86_64-linux"`
 - host os: `Linux 5.16.13-xanmod1-lantian, NixOS, 22.05 (Quokka)`
 - multi-user?: `yes`
 - sandbox: `yes`
 - version: `nix-env (Nix) 2.8.0pre20220311_d532269`
 - nixpkgs: `/etc/nix/inputs/nixpkgs`

In reply to @winterqt:nixos.dev
I wish there was a way we could parallelize the derivation copy step for buildOnTarget, this takes ages on large upgrades >.<

In reply to @zhaofeng:zhaofeng.li
I looked at it, and it appears that Nix used to be able to copy paths in parallel, but it's disabled for some reason: https://discourse.nixos.org/t/speed-up-nix-copy/15884/5

Nixops has the convenient --exclude option that allows deploying every node except the given ones. This would be nice to have in colmena as well, particularly in combination with the tags feature.

• Suppose I have a headless machine with link-local connectivity
• That machine has a specially prepared live iso with a well-known (static & link-local) ip address
• The mount point of the store is to be construed at /mnt/nix/...
• Let's call the still anonymous host (no own IP, no crypto identiy) larva
• Now we want to: colmena apply --on larva --over [fe80::47]:2222 --store /mnt/nix

Can you give me a few pointers where to implement this?

What would be the conceptual steps for feature parity with deploy-rs and enable deployment of home-manager profiles as a "grand unified deployment tool"?