nix copy: Move --from / --to check
nix copy: Move --from / --to check

This means you now get an error message *before* stuff gets built:

  $ nix copy .#hydraJobs.vendoredCrates
  error: you must pass '--from' and/or '--to'
  Try 'nix --help' for more information.

NixOS/nix,rycee/nix,rycee/nix,rycee/nix,NixOS/nix,rycee/nix,NixOS/nix,NixOS/nix,NixOS/nix,rycee/nix