[BUG] `extraFiles` fails when `source` is a directory

[daniellaing]

Plugin

No response

Nixpkgs Release

unstable

Home Manager Release

None

I have read the FAQ

• I have read the FAQ and my bug is not listed there.

Description

Just the title.

Fails with the following error:

error: Cannot build '/nix/store/g6zhk1l7bc5w6rmmj9l0fbh7w1i0j23z-nvim-config.drv'.
       Reason: builder failed with exit code 1.
       Output paths:
         /nix/store/pdlwp52il52kgjkcl36yf03rffbzh166-nvim-config
       Last 1 log lines:
       > cp: -r not specified; omitting directory '/nix/store/15b81403vyciiqw98ihz61dn9y73x978-lua'
       For full logs, run:
         nix log /nix/store/g6zhk1l7bc5w6rmmj9l0fbh7w1i0j23z-nvim-config.drv

Minimal, Reproducible Example (MRE)

programs.nixvim = {
    # Where lua is a directory, for example, of lua files to include.
    extraFiles."example".source = ./lua;
};

[daniellaing]

Is it as simple as adding -r flag here?

nixvim/modules/top-level/files/default.nix

Line 87 in f1e07ba

cp "$src" "$out/$target"

[MattSturgeon]

Thanks for opening the issue and investigating.

Is it as simple as adding -r flag here?

That's definitely the problematic line.

OTTOMH, I can't recall how cp -r behaves with non-directories. But, yes. Something like that should resolve this, I'd be happy to review a PR 😁

---

Looking upstream, it seems the etc module has had some improvements since I last looked at it.

https://github.com/NixOS/nixpkgs/blob/2fad6eac6077f03fe109c4d4eb171cf96791faa4/nixos/modules/system/etc/etc.nix#L21-L53

It now uses symlinks instead of copying, manually implements path globing, and manually detects path collisions. One advantage of copying files is that you can often merge collisions (if the collisions relate to directories), but the disadvantage is you end up with the same file in-store twice.

[daniellaing]

Is there a way to just use the upstream implementation of this? That way nixvim doesn't have to maintain its own copy

[MattSturgeon]

Not without major refactoring upstream to generalise that implementation for reuse in other situations.

[daniellaing]

What do you think is the best way to procede?
I can easily open a PR adding the -r flag, or have a look at another kind of fix if you have any in mind? I'm sure you have a much wider and fuller knowledge of the code here than me!