Prevent Project Directory from Being Copied into /nix/store

[x-0D]

Description:

Currently, the behavior of the devenv tool includes copying the project directory (specified by $DEVENV_ROOT_FILE) into the /nix/store. This can lead to issues related to storage management and unwanted duplication of project files.

Expected Behavior:

The project directory should remain in its original location without being duplicated in the /nix/store. This will help maintain a cleaner environment and avoid potential conflicts or confusion arising from multiple copies of the same files.

Steps to Reproduce:

1. Set up a project using devenv flake.nix with .envrc file .
2. Run the direnv allow to initialize or build the environment.
3. Check the /nix/store for any copies (*-source) of the project directory.

Actual Behavior:

The project directory is copied into /nix/store, leading to unnecessary duplication and possible critical security leakage

Additional Information:

This issue has been observed in various setups and may affect users who rely on a clean Nix environment. A solution that prevents this behavior would enhance usability and efficiency for developers using devenv.

maybe related with: NixOS/nix#5551 NixOS/nix#3121 NixOS/nix#5574 and possible workaround direnv/direnv#1103

please, update the docs with example flakes configurations that don't store users project into /nix/store

[domenkozar]

It copies that only if you use flakes, not if you use devenv itself.