3363377530
By default, Perl versions since 5.8.1 use randomization to make hashes
resistant to complexity attacks.
That randomization makes building VM images such as ubuntu1804x86_64
non-deterministic because the (imported) derivations built by
deb/deb-closure.pl are not stable.
This can easily be observed by repeating the following sequence of
commands and noting the path of the image's .drv:
nix-instantiate -E '(import <nixpkgs> {}).vmTools.diskImageFuns.ubuntu1804x86_64 {}'
nix-store --delete /nix/store/*ubuntu-18.04-bionic-amd64.nix
One source of non-determinism is the handling of Provides/Replaces,
which depends on the order of iteration over %packages. Here is a
diff showing the corresponding change in output:
>>> awk
-virtual awk: using original-awk
- original-awk: libc6 (>= 2.14)
+virtual awk: using mawk
+ mawk: libc6 (>= 2.14)
- mawk: libc6 (>= 2.14)
->>> libc6
This patch sorts packages by name for Provides/Replaces processing,
which seems to result in stable output.
(If the above turns out not to be sufficient, one could also set the
PERL_HASH_SEED and PERL_PERTURB_KEYS environment variables, documented
in 'perlrun', to disable Perl's built-in randomization. Complexity
attacks are not an issue as we control and trust all inputs.)
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|---|---|---|
| .github | ||
| doc | ||
| lib | ||
| maintainers | ||
| nixos | ||
| pkgs | ||
| .editorconfig | ||
| .gitattributes | ||
| .gitignore | ||
| .version | ||
| COPYING | ||
| default.nix | ||
| flake.nix | ||
| README.md | ||
Nixpkgs is a collection of over 60,000 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 expressions (programs), and how to use Nix command line tools
Community
- Discourse Forum
- IRC - #nixos on freenode.net
- NixOS Weekly
- Community-maintained wiki
- Community-maintained list of ways to get in touch (Discord, Matrix, Telegram, other IRC channels, etc.)
Other Project Repositories
The sources of all official Nix-related projects are in the NixOS organization on GitHub. Here are some of the main ones:
- Nix - the purely functional package manager
- NixOps - the tool to remotely deploy NixOS machines
- nixos-hardware - NixOS profiles to optimize settings for different hardware
- Nix RFCs - the formal process for making substantial changes to the community
- NixOS homepage - the NixOS.org website
- hydra - our continuous integration system
- NixOS Artwork - NixOS artwork
Continuous Integration and Distribution
Nixpkgs and NixOS are built and tested by our continuous integration system, Hydra.
- Continuous package builds for unstable/master
- Continuous package builds for the NixOS 20.09 release
- Tests for unstable/master
- Tests for the NixOS 20.09 release
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.
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 tens of thousands of 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:
masteris the main branch where all small contributions gostagingis branched from master, changes that have a big impact on Hydra builds go to this branchstaging-nextis 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.