Non-determinism in evaluation of flake.lock with subflakes?

[solomon-b]

I use subflakes to manage some dependencies that get input into my main system flake. I inconsistently get flake.lock related errors when deploying. Sometimes running the deploy command a couple times solves the issue but other times I am forced to do a nix flake update to regen my pins.

➜ colmena apply --on sower  
warning: Git tree '/home/solomon/Development/Nix/nixos-config' is dirty
[INFO ] Using flake: git+file:///home/solomon/Development/Nix/nixos-config
[INFO ] Enumerating nodes...
warning: Git tree '/home/solomon/Development/Nix/nixos-config' is dirty
warning: Git tree '/home/solomon/Development/Nix/nixos-config' is dirty
warning: Git tree '/home/solomon/Development/Nix/nixos-config' is dirty
error: 'lastModified' attribute mismatch in input 'path:/home/solomon/Development/Nix/nixos-config/flakes/xmonad-solomon?lastModified=1682727605&narHash=sha256-3nO1aJ8C8oZtT1Z5vckY1sEeColrTx+8zQEUeGPcn1U=', expected 0
(use '--show-trace' to show detailed location information)
[ERROR] -----
[ERROR] Operation failed with error: Child process exited with error code: 1

➜ colmena apply --on sower
warning: Git tree '/home/solomon/Development/Nix/nixos-config' is dirty
[INFO ] Using flake: git+file:///home/solomon/Development/Nix/nixos-config
[INFO ] Enumerating nodes...
warning: Git tree '/home/solomon/Development/Nix/nixos-config' is dirty
warning: Git tree '/home/solomon/Development/Nix/nixos-config' is dirty
warning: Git tree '/home/solomon/Development/Nix/nixos-config' is dirty
[INFO ] Selected 1 out of 9 hosts.
      ✅ 70s All done!
sower ✅ 8s Evaluated sower
sower ✅ 24s Built "/nix/store/mw4vd3285b9pb2a5z10q5xfarci1vm5r-nixos-system-sower-22.11pre-git"
sower ✅ 31s Pushed system closure
sower ✅ 7s Activation successful