Allows detecting whether attributes are overridden in all-packages.nix.
In a future commit we'll use this to detect empty arguments being set in
all-packages.nix and complain about that.
We seem to have enough tests to run into this now:
error: creating symlink from '/private/tmp/nix-build-nixpkgs-check-by-name.drv-0/source/test-tmp/var/nix/gcroots/profiles' to '/private/tmp/nix-build-nixpkgs-check-by-name.drv-0/source/test-tmp/var/nix/profiles': File exists
On Darwin, /tmp is sometimes a symlink to /private/tmp, which couldn't
be handled before:
error: access to canonical path '/private/var/folders/xp/9_ry6h9x6l9gh_g32qspz0_40000gp/T/.tmpFbcNO0' is forbidden in restricted mode
This both fixes that and adds a test to make sure it can't happen again
This introduces the `pkgs/by-name` directory as proposed by RFC 140.
Included are:
- The implementation to add packages defined in that directory to the
top-level package scope
- Contributer documentation on how to add packages to it
- A GitHub Actions workflow to check the structure of it on all PRs
- Better filesystem case-sensitivity heuristic
We shouldn't assume that Linux is always case-sensitive.
- Don't include case-sensitive filename in tree
Was used for tests, but this broke channel updates because there's a
check to make sure there's no case-sensitive files!
https://hydra.nixos.org/build/233371356/nixlog/1
