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John Ericson 63bd851e95 stdenv: Introduce hasCC attribute
Before, we'd always use `cc = null`, and check for that. The problem is
this breaks for cross compilation to platforms that don't support a C
compiler.

It's a very subtle issue. One might think there is no problem because we
have `stdenvNoCC`, and presumably one would only build derivations that
use that. The problem is that one still wants to use tools at build-time
that are themselves built with a C compiler, and those are gotten via
"splicing". The runtime version of those deps will explode, but the
build time / `buildPackages` versions of those deps will be fine, and
splicing attempts to work this by using `builtins.tryEval` to filter out
any broken "higher priority" packages (runtime is the default and
highest priority) so that both `foo` and `foo.nativeDrv` works.

However, `tryEval` only catches certain evaluation failures (e.g.
exceptions), and not arbitrary failures (such as `cc.attr` when `cc` is
null). This means `tryEval` fails to let us use our build time deps, and
everything comes apart.

The right solution is, as usually, to get rid of splicing. Or, baring
that, to make it so `foo` never works and one has to explicitly do
`foo.*`. But that is a much larger change, and certaily one unsuitable
to be backported to stable.

Given that, we instead make an exception-throwing `cc` attribute, and
create a `hasCC` attribute for those derivations which wish to
condtionally use a C compiler: instead of doing `stdenv.cc or null ==
null` or something similar, one does `stdenv.hasCC`. This allows quering
without "tripping" the exception, while also allowing `tryEval` to work.

No platform without a C compiler is yet wired up by default. That will
be done in a following commit.
2019-11-25 00:12:38 +00:00
.github CODEOWNERS: Add myself as owner for emacs 2019-08-30 17:23:13 +01:00
doc doc: Fix and clarify `allowInsecurePredicate` example 2019-11-24 17:36:17 +00:00
lib lib: Add getName to mirror getVersion 2019-11-24 16:24:50 +00:00
maintainers treewide: Get rid of most `parseDrvName` without breaking compat 2019-11-24 17:22:28 +00:00
nixos treewide: Get rid of most `parseDrvName` without breaking compat 2019-11-24 17:22:28 +00:00
pkgs stdenv: Introduce hasCC attribute 2019-11-25 00:12:38 +00:00
.editorconfig Revert ".version: remove final newline" 2018-04-28 14:23:13 +02:00
.gitattributes gitattributes: disable merge=union in all-packages 2018-03-27 11:03:03 -05:00
.gitignore Replace androidenv by new implementation 2018-12-18 21:16:06 +01:00
.version 19.09 is Loris. 2019-02-25 23:21:14 +01:00
COPYING COPYING: include 2019 2019-03-18 19:55:33 -07:00
README.md README.md: improve content 2019-09-07 22:33:22 -07:00
default.nix Fix local path to release notes in error message 2018-10-08 05:43:15 -05:00

README.md

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Nixpkgs is a collection of over 40,000 software packages that can be installed with the Nix package manager. It also implements NixOS, a purely-functional Linux distribution.

Manuals

  • NixOS Manual - how to install, configure, and maintain a purely-functional Linux distribution
  • Nixpkgs Manual - contributing to Nixpkgs and using programming-language-specific Nix expressions
  • Nix Package Manager Manual - how to write Nix expresssions (programs), and how to use Nix command line tools

Community

Other Project Repositories

The sources of all offical Nix-related projects are in the NixOS organization on GitHub. Here are some of the main ones:

Continuous Integration and Distribution

Nixpkgs and NixOS are built and tested by our continuous integration system, Hydra.

Artifacts successfully built with Hydra are published to cache at https://cache.nixos.org/. When successful build and test criteria are met, the Nixpkgs expressions are distributed via Nix channels. The channels are provided via a read-only mirror of the Nixpkgs repository called nixpkgs-channels.

Contributing

Nixpkgs is among the most active projects on GitHub. While thousands of open issues and pull requests might seem a lot at first, it helps consider it in the context of the scope of the project. Nixpkgs describes how to build over 40,000 pieces of software and implements a Linux distribution. The GitHub Insights page gives a sense of the project activity.

Community contributions are always welcome through GitHub Issues and Pull Requests. When pull requests are made, our tooling automation bot, OfBorg will perform various checks to help ensure expression quality.

The Nixpkgs maintainers are people who have assigned themselves to maintain specific individual packages. We encourage people who care about a package to assign themselves as a maintainer. When a pull request is made against a package, OfBorg will notify the appropriate maintainer(s). The Nixpkgs committers are people who have been given permission to merge.

Most contributions are based on and merged into these branches:

  • master is the main branch where all small contributions go
  • staging is branched from master, changes that have a big impact on Hydra builds go to this branch
  • staging-next is branched from staging and only fixes to stabilize and security fixes with a big impact on Hydra builds should be contributed to this branch. This branch is merged into master when deemed of sufficiently high quality

For more information about contributing to the project, please visit the contributing page.

Donations

The infrastructure for NixOS and related projects is maintained by a nonprofit organization, the NixOS Foundation. To ensure the continuity and expansion of the NixOS infrastructure, we are looking for donations to our organization.

You can donate to the NixOS foundation by using Open Collective:

License

Nixpkgs is licensed under the MIT License.

Note: MIT license does not apply to the packages built by Nixpkgs, merely to the files in this repository (the Nix expressions, build scripts, NixOS modules, etc.). It also might not apply to patches included in Nixpkgs, which may be derivative works of the packages to which they apply. The aforementioned artifacts are all covered by the licenses of the respective packages.