From NixOS Wiki
Jump to: navigation, search
(mention home-manager as a possible declarative setup in addition to the pure nix solution.)
(Add warning about the new wiki)
Line 1: Line 1:
 +
{{warning|1=You are reading an article on the deprecated unofficial wiki. For the up to date version of this article, see https://wiki.nixos.org/wiki/FAQ/Why_not_use_nix-env_-i_foo?.}}
 +
 
{{FAQ/breadcrumb}}{{#tweekihide:firstHeading}}<onlyinclude>
 
{{FAQ/breadcrumb}}{{#tweekihide:firstHeading}}<onlyinclude>
 
== Why not use nix-env -i hello? ==
 
== Why not use nix-env -i hello? ==

Revision as of 16:29, 4 April 2024

Warning: You are reading an article on the deprecated unofficial wiki. For the up to date version of this article, see https://wiki.nixos.org/wiki/FAQ/Why_not_use_nix-env_-i_foo?.

Why not use nix-env -i hello?

nix-env -i hello is slower and tends to be less precise than nix-env -f '<nixpkgs>' -iA hello. This is because it will evaluate all of nixpkgs searching for packages with the name hello, and install the one determined to be the latest (which may not even be the one that you want). Meanwhile, with -A, nix-env will evaluate only the given attribute in nixpkgs. This will be significantly faster, consume significantly less memory, and more likely get you what you want.

nix-env -u has the same problem, searching for all the packages in the user environment by name and upgrading them. This may lead to unwanted major-version upgrades like JDK 8 → JDK 9. If you want to have a declarative user environment, you may wish to use Home Manager. It is also possible to home-bake a pure nix solution like LnL's. With this setup, you can update your packages by simply running nix-rebuild.