Allow forcing Nix to ignore Git/version control information inside a flake

[lina-bh]

Is your feature request related to a problem? Please describe.
My problem is that before flakes I would add all of the NixOS modules that I wanted to sync, except for hardware-configuration.nix which I don't want to upload to GitHub or wherever, and configuration.nix which I use for scratch configuration that I don't want to synchronise. Flakes, using them how you would normally in /etc/nixos/flake.nix breaks this workflow, because it always considers a directory with a .git subdirectory a git repository and then won't copy files that aren't added to the git index to the store.

Describe the solution you'd like
A way to force Nix to ignore .git (or .hg, for that matter) when given a path: input, inside the flake file. I would think it would look something like this:

{ inputs.gitdir = { url = "path:/to/git/directory"; vcs = false; }; }

I think making it a command line option would be a poor idea, because you end up having to remember to specify them every single time.

Describe alternatives you've considered
Currently I use a trick to confuse Nix into not following into the git repository where I store my configuration by using two flake files. One simple one that exports modules in nixosModules, and another that specifies nixpkgs input and imports that flake, which I then hard link into /etc/nixos so Nix doesn't know it's inside a git repository.

Additional context
N/A? I think I could work on this myself, but I would have to bring myself up to speed on how the Nix source expects me to access the parsed information from the flake file.

[L-as]

I don't think this is really useful, because you're really doing this the entirely wrong way.

You want a flake for your modules which you can upload, then another per-machine flake. You can also use Git for both then. The per-machine flake would have the shared flake as a flake input.