error.md

I just want to say I got the most wonderful error message from a Nix evaluation today:

trace: warning: In file [...]/packet-spot-buildkite-agent/network.nix
a list is being assigned to the option config.programs.ssh.knownHosts.
This will soon be an error as type loaOf is deprecated.
See https://git.io/fj2zm for more information.
Do
  programs.ssh.knownHosts =
    { flexo.gsc.io = {...}; }
instead of
  programs.ssh.knownHosts =
    [ { hostNames = [ "flexo.gsc.io" "r13y.com" "147.75.105.137" ]; ...} ]

This error message:

✔️ is specific: "a list is being assigned to the option config.programs.ssh.knownHosts"

✔️ tells me where to go for more information: https://git.io/fj2zm

✔️ tells me where the violation is: .../packet-spot-buildkite-agent/network.nix

✔️ SHOWS me the code which is wrong:

      programs.ssh.knownHosts =
        [ { hostNames = [ "flexo.gsc.io" "r13y.com" "147.75.105.137" ]; ...} ]

✔️ AND tells me the solution:

      programs.ssh.knownHosts =
        { flexo.gsc.io = {...}; }

This is incredible, and ticks the main three boxes of good errors:

1. What is the problem?
2. Why did it happen?
3. How do I fix it?

Way to go everyone, this is a massive step forward for our community and I am completely floored and delighted. Thank you.

Great warning message indeed! :D

One question though, what would you do if you have multiple hostnames associated with the same publicKey? Would you associate the same key to every hostname entry?