faster nix evaluate warning

[phucisstupid]

Question:

I’m getting this warning when using Nix with my flake setup:

warning: Copying '/Users/wow/dotfiles/' to the store again
You can make Nix evaluate faster and copy fewer files by replacing `./.` with the `self` flake input, or `builtins.path { path = ./.; name = "source"; }`

Currently, I’m using something like:

src = ./.;

I don't understand what it’s suggesting I should use self or builtins.path instead?. Can someone explain.