_coreMachines = import "${super.morph.lib}/eval-machines.nix" {                                                                                                                                                                        
          networkExpr = ../../network.nix;                                                                                                                                                                                                     
        };                                                                                                                                                                                                                                     
                                                                                                                                                                                                                                               
         coreMachines = if config._module.args ? nodes                                                                                                                                                                                        
                        then config._module.args.nodes                                                                                                                                                                                        
                        else _coreMachines.nodes;                  

{ machine }:                                                                                                                                                                                                                                   
{ ... }:                                                                                                                                                                                                                                       
let                                                                                                                                                                                                                                            
  nixpkgs = import <nixpkgs> {};                                                                                                                                                                                                               
  # Evaluate a morph network.                                                                                                                                                                                                                  
  evaluateMorph = networkExpr: import "${nixpkgs.morph.lib}/eval-machines.nix" {                                                                                                                                                               
    inherit networkExpr;                                                                                                                                                                                                                       
  };                                                                                                                                                                                                                                           
  morphResult = evaluateMorph ../network.nix;                                                                                                                                                                                                  
in {                                                                                                                                                                                                                                           
  "${machine}" = morphResult.nodes.${machine}.config.system.build.toplevel;                                                                                                                                     
}  

anyone else noticing that targets in a flake don't substitute from cache.nixos.org when running colmena apply?
I haven't investigated further yet.
But I did notice that disabling nix copy seems to fix it 👀

really dump patch, as there is no cmd flag to disable it (running latest main):

diff --git a/src/nix/host/ssh.rs b/src/nix/host/ssh.rs
index d45ed99..1b33717 100644
--- a/src/nix/host/ssh.rs
+++ b/src/nix/host/ssh.rs
@@ -261,7 +261,7 @@ impl Ssh {
         let ssh_options = self.ssh_options();
         let ssh_options_str = ssh_options.join(" ");
 
-        let mut command = if self.use_nix3_copy {
+        let mut command = if false {
             // experimental `nix copy` command with ssh-ng://
             let mut command = Command::new("nix");

In reply to @askyourself:askyourself.ca
I upgraded my config to use flake-parts, it's really nice but I'm having trouble integrating colmena.