My first Nix derivation

Does precisely nothing, but I’m inexplicably excited 😛

nix-repl> d = derivation { name = "foo"; builder = "${bash}/bin/bash"; args = [ ./builder.sh ]; system = builtins.currentSystem; }

nix-repl> :b d
[1 built, 0.0 MiB DL]

this derivation produced the following outputs:
  out -> /nix/store/l23m6a2fkidklr8plhkb6iwl5x690c7h-foo