[Nix#9574] Broken `NIX_PATH` tracking issue #89

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opened 2024-03-16 06:44:51 +00:00 by lix-bot · 3 comments

lix-bot commented

2024-03-16 06:44:51 +00:00

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Upstream-Issue: NixOS/nix#9574

Describe the bug

NIX_PATH environment variable does not work when nix.conf has a nix-path setting.
This is highly unexpected and not intentional.
Multiple issues and PRs exist, but solving this problem has proven difficult within the established abstractions for settings handling.

Issues

#8784
#8890

PRs

#7871
#8902

Priorities

Add 👍 to issues you find important.

Upstream-Issue: https://git.lix.systems/NixOS/nix/issues/9574 **Describe the bug** `NIX_PATH` environment variable does not work when `nix.conf` has a `nix-path` setting. This is highly unexpected and not intentional. Multiple issues and PRs exist, but solving this problem has proven difficult within the established abstractions for settings handling. **Issues** - #8784 - #8890 **PRs** - #7871 - #8902 **Priorities** Add :+1: to [issues you find important](https://github.com/NixOS/nix/issues?q=is%3Aissue+is%3Aopen+sort%3Areactions-%2B1-desc).

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piegames commented

2024-05-06 20:27:56 +00:00

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To quote myself on the GitHub side:

While this is definitely a Nix bug, I'd argue that the NixOS module is broken as well: The nix.nixPath option sets environment.sessionVariables.NIX_PATH instead of settings.nix-path, which is surprising.

However, even with both of these fixed, I'd argue that the general behavior and interaction between these two would be suboptimal and surprising: If one configures the Nix path through nix.conf and then a script goes along and wants to append to NIX_PATH, it will effectively override the existing path instead of appending, which is clearly not intended. (The alternative of appending/merging both is equally problematic for other reasons. Maybe the two simply should not coexist …)

How feasible would it be to remove nix-path from nix.conf?

To quote myself on the GitHub side: > While this is definitely a Nix bug, I'd argue that the NixOS module is broken as well: The `nix.nixPath` option sets `environment.sessionVariables.NIX_PATH` instead of `settings.nix-path`, which is surprising. > > However, even with both of these fixed, I'd argue that the general behavior and interaction between these two would be suboptimal and surprising: If one configures the Nix path through `nix.conf` and then a script goes along and wants to append to `NIX_PATH`, it will effectively override the existing path instead of appending, which is clearly not intended. (The alternative of appending/merging both is equally problematic for other reasons. Maybe the two simply should not coexist …) How feasible would it be to remove `nix-path` from `nix.conf`?

raito commented

2024-05-06 21:59:19 +00:00

Owner

It seems to be used to disable channel in NixOS (not in home-manager):

nixos/modules/config/nix-channel.nix
97:    nix.settings.nix-path = mkIf (! cfg.channel.enable) (mkDefault "");

nixos/tests/nix-config.nix
6:      nix-path = [ "nonextra=/etc/value.nix" ];
7:      extra-nix-path = [ "extra=/etc/value.nix" ];

Other than that, I don't see any blocker.

It seems to be used to disable channel in NixOS (not in home-manager): ``` nixos/modules/config/nix-channel.nix 97: nix.settings.nix-path = mkIf (! cfg.channel.enable) (mkDefault ""); nixos/tests/nix-config.nix 6: nix-path = [ "nonextra=/etc/value.nix" ]; 7: extra-nix-path = [ "extra=/etc/value.nix" ]; ``` Other than that, I don't see any blocker.