nixpkgs manual introduction: improve

- make line wrapping more consistent (overlong lines)
- don't stress the manual is *only* for contributors,
  as it does contain some user-guide parts, including the intro itself
- since March our Hydra publishes binaries immediately,
  not waiting for channel update
This commit is contained in:
Vladimír Čunát 2016-04-05 09:56:32 +02:00
parent d2ef7ab10f
commit 2bbae9696a

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@ -6,13 +6,14 @@ date: 2015-11-25
# Introduction
The Nix Packages collection (Nixpkgs) is a set of over 30,000 packages for the
[Nix package manager](http://nixos.org/nix/), released under a [permissive MIT/X11 license](https://github.com/NixOS/nixpkgs/blob/master/COPYING).
Packages are available for several architectures, and can be used with the Nix package manager
on most GNU/Linux distributions as well as NixOS.
The Nix Packages collection (Nixpkgs) is a set of thousands of packages for the
[Nix package manager](http://nixos.org/nix/), released under a
[permissive MIT/X11 license](https://github.com/NixOS/nixpkgs/blob/master/COPYING).
Packages are available for several platforms, and can be used with the Nix
package manager on most GNU/Linux distributions as well as NixOS.
This manual describes how to write packages for the Nix Packages collection
(Nixpkgs). Thus its for packagers and developers who want to add packages to
This manual primarily describes how to write packages for the Nix Packages collection
(Nixpkgs). Thus its mainly for packagers and developers who want to add packages to
Nixpkgs. If you like to learn more about the Nix package manager and the Nix
expression language, then you are kindly referred to the [Nix manual](http://nixos.org/nix/manual/).
@ -20,29 +21,33 @@ expression language, then you are kindly referred to the [Nix manual](http://nix
Nix expressions describe how to build packages from source and are collected in
the [nixpkgs repository](https://github.com/NixOS/nixpkgs). Also included in the
collection are Nix expressions for [NixOS modules](http://nixos.org/nixos/manual/index.html#sec-writing-modules). With
these expressions the Nix package manager can build binary packages.
collection are Nix expressions for
[NixOS modules](http://nixos.org/nixos/manual/index.html#sec-writing-modules).
With these expressions the Nix package manager can build binary packages.
Packages, including the Nix packages collection, are distributed through
[channels](http://nixos.org/nix/manual/#sec-channels). The collection is
distributed for users of Nix on non-NixOS distributions through the channel
`nixpkgs`. Users of NixOS generally use one of the `nixos-*` channels, e.g.
`nixos-15.09`, which includes all packages and modules for the stable NixOS
15.09. The channels of the stable NixOS releases are generally only given
`nixos-16.03`, which includes all packages and modules for the stable NixOS
16.03. The purpose of stable NixOS releases are generally only given
security updates. More up to date packages and modules are available via the
`nixos-unstable` channel.
Both `nixos-unstable` and `nixpkgs` follow the `master` branch of the Nixpkgs
repository, although both do lag the `master` branch by generally [a couple of days](http://howoldis.herokuapp.com/). Updates to a channel are distributed as
soon as all tests for that channel pass, e.g. [this table](http://hydra.nixos.org/job/nixpkgs/trunk/unstable#tabs-constituents)
repository, although both do lag the `master` branch by generally
[a couple of days](http://howoldis.herokuapp.com/). Updates to a channel are
distributed as soon as all tests for that channel pass, e.g.
[this table](http://hydra.nixos.org/job/nixpkgs/trunk/unstable#tabs-constituents)
shows the status of tests for the `nixpkgs` channel.
The tests are conducted by a cluster called [Hydra](http://nixos.org/hydra/),
which also builds binary packages from the Nix expressions in Nixpkgs. As soon
as a channel is updated, the binaries are made available via a [binary cache](https://cache.nixos.org). Until the channel updates, binaries that have
already been built, are available via [Hydra's binary cache](https://hydra.nixos.org).
which also builds binary packages from the Nix expressions in Nixpkgs for
`x86_64-linux`, `i686-linux` and `x86_64-darwin`.
The binaries are made available via a [binary cache](https://cache.nixos.org).
The current Nix expressions of the channels are available in the
[`nixpkgs-channels`](https://github.com/NixOS/nixpkgs-channels) repository,
which has branches corresponding to the available channels. There is also the
Nixpkgs Monitor which keeps track of updates and security vulnerabilities.
[Nixpkgs Monitor](http://monitor.nixos.org) which keeps track of updates
and security vulnerabilities.