sternenseemann
9d6cac3e53
Currently the throw codepath will never be hit. Specifically it doesn't
guard against a misuse of the hook:
pkgsCross.aarch64-multiplatform.mesonEmulatorHook # this should fail
pkgsCross.aarch64-multiplatform.buildPackages.mesonEmulatorHook # this should (and does) succeed
The check sort of worked to guard against use in situations where the
hook wasn't misplaced between nativeBuildInputs and buildInputs, but
the build platform was actually able to execute binaries built for the
host platform.
This worked because nativeBuildInputs would first of all need to
evaluate pkgsHostTarget.mesonEmulatorHook in order to access the spliced
derivation it wants, pkgsBuildHost.mesonEmulatorHook. For this, you'd
need to pass the if expression, at which point buildPlatform and
targetPlatform would match the build and target platform of the
derivation that uses the hook. Consequently the check is “correct”,
since it is its build platform that needs not to be able execute stuff
built for its host platform.
The target platform is technically wrong here, but it works out
since (at least currently) in nixpkgs either build and host or host and
target platform are equal. When doing the check in pkgsHostTarget,
target and host platform are equal.
However, this is a kind of incomprehensible rube goldberg machine, let's
some mistakes slip through the cracks and relies on implementation
details of splicing.
To alleviate this, we do the following:
- We move the check _into_ the derivation. By doing the check when
obtaining the file for the setup hook and not before calling
`makeSetupHook`. This means that we can force `mesonEmulatorHook`
even if forcing `mesonEmulatorHook.outPath` would throw. This ensures
that splicing can work even if the some of the derivation variants
would fail to evaluate.
- Since splicing works now, we can no longer have to do the check
“globally” before splicing happens. This means we can use the setup
hook derivation's own platforms. buildPlatform is irrelevant here,
since this is only the platform on which the shell script is put
together. hostPlatform matters, since it is were the setup hook is
executed later (i.e. the using derivation's build platform). target
platform is the platform the adjacent meson builds executables for,
i.e. the platform we may need to emulate for.
To verify this change, I have evaluated all derivations using
mesonEmulatorHook in `pkgsCross.aarch64-multiplatform` before and after
this change. The hashes don't change.
Nixpkgs is a collection of over 80,000 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
- Matrix Chat
- NixOS Weekly
- Community-maintained wiki
- Community-maintained list of ways to get in touch (Discord, Telegram, IRC, 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 23.05 release
- Tests for unstable/master
- Tests for the NixOS 23.05 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 through SEPA bank transfers or 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.