Nix (package manager): Difference between revisions

{{Disambiguation|message=<translate>This article is about the Nix package manager. Not to be confused with the [[<tvar name="1">Nix ecosystem</tvar>|Nix ecosystem]], the [[<tvar name="2">Nix (language)</tvar>|Nix language]] or the [[<tvar name="3">Nix (command)</tvar>|Nix command]].</translate>}}

Nix is a package manager and build system that parses reproducible build instructions specified in the [[<tvar name="1">Nix (language)</tvar>|Nix Expression Language]], a pure functional language with lazy evaluation. Nix expressions are pure functions<ref>Values cannot change during computation. Functions always produce the same output if their input does not change.</ref> taking dependencies as arguments and producing a ''[[<tvar name="2">Derivations</tvar>|derivation]]'' specifying a reproducible build environment for the package. Nix stores the results of the build in unique addresses specified by a hash of the complete dependency tree, creating an immutable package store (aka the [[#Nix store|nix store]]) that allows for atomic upgrades, rollbacks and concurrent installation of different versions of a package, essentially eliminating [[<tvar name="3">Wikipedia:Dependency hell</tvar>|dependency hell]].