nix dump-path requires nix-command to be enabled

[flokli]

Describe the bug

❯ nix dump-path /nix/store/kwmqk7ygvhypxadsdaai27gl6qfxv7za-hello-2.12.1
warning: 'dump-path' is a deprecated alias for 'store dump-path'
error: experimental Nix feature 'nix-command' is disabled; use '--extra-experimental-features nix-command' to override

Used to work fine in Nix 2.3, and probably a few other recent Nix versions.

Used in nix-serve for example: https://github.com/edolstra/nix-serve/blob/master/nix-serve.psgi#L66, effectively breaking it on systems without nix-command being enabled.

Expected behavior

Don't gate nix dump-path behind the nix-command xp. It was "stable" before, and there's code (like nix-serve) out there relying on it.

nix-env --version output

nix-env (Nix) 2.18.5

Additional context

Add any other context about the problem here.

Priorities

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[edolstra]

I can't reproduce this.

nix --experimental-features 'nix-command' store dump-path /nix/store/94d0gz9z6kbc8x5qqisdhjrap6y9casd-coreutils-full-9.5 > /dev/null

works fine.

Note that if you run nix store dump-path without arguments in a flake directory, it will try to evaluate the flake, which requires the flakes experimental feature.

[flokli]

See NixOS/nixpkgs#331230, try running the passthru tests from a nixpkgs checkout without adding Nix 2.3 to $PATH, but pkgs.nix.

[flokli]

Running it without a parameter indeed exposes the flake behaviour (and error message).

The nixpkgs test is however also failing, due to the nix-command commands being made experimental again. I updated the issue accordingly.

[edolstra]

The nix CLI was always experimental, but wasn't feature-gated initially. It will become stable again in the future (see #7701).

[nixos-discourse]

This issue has been mentioned on NixOS Discourse. There might be relevant details there:

https://discourse.nixos.org/t/2024-07-31-nix-team-meeting-minutes-166/49972/1