53c5f08415
Relying on `.attrs.sh` to exist in `$NIX_BUILD_TOP` is problematic
because that's not compatible with how `nix-shell(1)` behaves. It places
`.attrs.{json,sh}` into a temporary directory and makes them accessible via
`$NIX_ATTRS_{SH,JSON}_FILE` in the environment[1]. The sole reason that
`nix-shell(1)` still works with structured-attrs enabled derivations
is that the contents of `.attrs.sh` are sourced into the
shell before sourcing `$stdenv/setup` (if `$stdenv` exists) by `nix-shell`.
However, the assumption that two files called `.attrs.sh` and
`.attrs.json` exist in `$NIX_BUILD_TOP` is wrong in an interactive shell
session and thus an inconsistency between shell debug session and actual
builds which can lead to unexpected problems.
To be precise, we currently have the following problem: an expression
like
with import ./. {};
runCommand "foo" { __structuredAttrs = true; foo.bar = [ 1 2 3 ]; }
''
echo "''${__structuredAttrs@Q}"
touch $out
''
prints `1` in its build-log. However when building interactively in a
`nix-shell`, it doesn't.
Because of that, I'm considering to propose a full deprecation of
`$NIX_BUILD_TOP/.attrs.{json,sh}`. A first step is to only mention the
environment variables, but not the actual paths anymore in Nix's
manual[2]. The second step - this patch - is to fix nixpkgs' stdenv
accordingly.
Please note that we cannot check for `-e "$NIX_ATTRS_JSON_FILE"` because
certain outdated Nix minors (that are still in the range of supported
Nix versions in `nixpkgs`) have a bug where `NIX_ATTRS_JSON_FILE` points
to the wrong file while building[3].
Also, for compatibility with Nix 2.3 which doesn't provide these
environment variables at all we still need to check for the existence of
.attrs.json/.attrs.sh here. As soon as we bump nixpkgs' minver to 2.4,
this can be dropped.
Finally, dropped the check for ATTRS_SH_FILE because that was never
relevant. In nix#4770 the ATTRS_SH_FILE variable was introduced[4] and
in a review iteration prefixed with NIX_[5]. In other words, these
variables were never part of a release and you'd only have this problem
if you'd use a Nix from a git revision of my branch from back then. In
other words, that's dead code.
[1] https://github.com/nixos/nix/pull/4770#issuecomment-834718851
[2] https://github.com/NixOS/nix/pull/9032
[3] https://github.com/NixOS/nix/issues/6736
[4]
|
||
|---|---|---|
| .github | ||
| doc | ||
| lib | ||
| maintainers | ||
| nixos | ||
| pkgs | ||
| .editorconfig | ||
| .git-blame-ignore-revs | ||
| .gitattributes | ||
| .gitignore | ||
| .mailmap | ||
| .version | ||
| CONTRIBUTING.md | ||
| COPYING | ||
| default.nix | ||
| flake.nix | ||
| README.md | ||
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.
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.