nix-direnv in the nixos-21.11 channel doesn’t work with flakes

[reckenrode]

Describe the bug

nix-direnv was updated in #145236 to assume that nix is 2.4, but that is no longer true after #147511 was merged. This causes .envrc files with use flake to fail to active the devShell.

Steps To Reproduce

Steps to reproduce the behavior:

1. Make sure your system is running NixOS 21.11 or is nix-darwin following the nixos-21.11 channel;
2. git clone https://github.com/reckenrode/verify-archive.git (or any project with a flake); and
3. cd verify-archive && direnv allow.

Expected behavior

The devShell specified in the flake is activated.

Screenshots

reckenrode@dyrstelice ~/D/verify-archive (main)> direnv allow
direnv: loading ~/Developer/verify-archive/.envrc
direnv: using flake
error: 'print-dev-env' is not a recognised command
Try '/nix/store/sbf432gsiw41ri4nqgrnxhvhbb9gidx4-nix-2.3.16/bin/nix --help' for more information.
error: 'flake' is not a recognised command
Try '/nix/store/sbf432gsiw41ri4nqgrnxhvhbb9gidx4-nix-2.3.16/bin/nix --help' for more information.
direnv: renewed cache
direnv: export ~XDG_DATA_DIRS

Additional context

Overriding nix in an overlay with nix_2_4 allows the flake to activate the devShell as expected.

Notify maintainers

@Mic92

Metadata

Please run nix-shell -p nix-info --run "nix-info -m" and paste the result.

reckenrode@dyrstelice ~> nix-shell -p nix-info --run "nix-info -m"
 - system: `"aarch64-darwin"`
 - host os: `Darwin 21.1.0, macOS 12.0.1`
 - multi-user?: `yes`
 - sandbox: `no`
 - version: `nix-env (Nix) 2.4`
 - channels(root): `""`
 - nixpkgs: `/etc/nix/inputs/nixpkgs`

Maintainer information:

# a list of nixpkgs attributes affected by the problem
attribute: nix-direnv
# a list of nixos modules affected by the problem
module:

[Mic92]

This is only for nixpkgs. There was also a home-manager module option that needs to be re-introduced: #147998

[SenchoPens]

Hi, had the same problem too, just updated and everything is fine, seems like it's fixed now. @reckenrode

[Mic92]

Yes. This was fixed in the linked pull requests.

[mainrs]

I'm using flakes for my configuration and I still exhibit the problem with these fixed inputs:

inputs = {
    home-manager.url = "github:nix-community/home-manager?ref=release-21.11";
    home-manager.inputs.nixpkgs.follows = "nixpkgs";
    nixpkgs.url = "github:NixOS/nixpkgs?ref=release-21.11";
    nixpkgs-unstable.url = "github:NixOS/nixpkgs/nixpkgs-unstable";
    nixops-plugged.url = "github:lukebfox/nixops-plugged";
    flake-utils.url = "github:numtide/flake-utils";
    nur.url = "github:nix-community/NUR";
  };

Inputs:
├───flake-utils: github:numtide/flake-utils/74f7e4319258e287b0f9cb95426c9853b282730b
├───home-manager: github:nix-community/home-manager/697cc8c68ed6a606296efbbe9614c32537078756
│   └───nixpkgs follows input 'nixpkgs'
├───nixops-plugged: github:lukebfox/nixops-plugged/d063dfc2a1ab3d62529716626b64964592230077
│   ├───flake-compat: github:edolstra/flake-compat/99f1c2157fba4bfe6211a321fd0ee43199025dbf
│   ├───flake-utils: github:numtide/flake-utils/b543720b25df6ffdfcf9227afafc5b8c1fabfae8
│   ├───nixpkgs: github:nixos/nixpkgs/efee454783c5c14ae78687439077c1d3f0544d97
│   └───poetry2nix: github:nix-community/poetry2nix/a5d82ecb020e6c058c0a515520a4e22133278b92
│       ├───flake-utils: github:numtide/flake-utils/3982c9903e93927c2164caa727cd3f6a0e6d14cc
│       └───nixpkgs: github:NixOS/nixpkgs/04af07c659c6723a2259bb6bc00a47ec53330f20
├───nixpkgs: github:NixOS/nixpkgs/d887ac7aee92e8fc54dde9060d60d927afae9d69
├───nixpkgs-unstable: github:NixOS/nixpkgs/5c37ad87222cfc1ec36d6cd1364514a9efc2f7f2
└───nur: github:nix-community/NUR/353ba5a371a0ebed815366b083d24caff3bc1582

Is this expected? Or am I doing something wrong?

[mainrs]

Looks like it was a configuration problem (nix-community/nix-direnv#122). Enabling programs.direnv.nix-direnv.enableFlakes=true solved the issue.