When running nix develop with these lines, I saw:

It was only building Emanote on macOS, but that's probably because I use a custom ema as input. Haven't tested it on emanote-template yet ...

I'm not sure if nixConfig from dependency (input, non-root) flakes apply, but it seems like they should. In that case these lines could be included in emanote, or ema.

The lines don't apply when used with nix run (NixOS/nix#6170). (But maybe running nix build first would prime the store? Not sure)

Also you can only add substitutors when running in a privileged context, which means:

• single user mode
• you are in trusted-users
• i guess portable nix etc

I'm not sure if nixConfig from dependency (input, non-root) flakes apply

They don't (NixOS/nix#4189 (comment))

Currently it only uses options from the top-level flake. Since dependencies are fetched lazily that's really the only option, unless we propagate options into the lock file.

, so adding the cache to emanote-template is desirable.

I haven't tested this, but maybe in a different PR we should update README with what works for cache and what doesn't. nix run and nix build are the main workflows for this repo.

maybe running nix build first would prime the store?

It seems to - nix run loads quickly after nix build with cache.