Nix build Not downloading everything from cache

Lyndeno · February 21, 2025, 7:42pm

Found the solution:

github.com/NixOS/nix

feat: add always-allow-substitutes

NixOS:master ← lovesegfault:always-allow-substitutes

opened 02:59PM - 14 Mar 23 UTC

lovesegfault

+12 -1

# Motivation This adds a new configuration option to Nix, `always-allow-subst…itutes`, whose effect is simple: it causes the `allowSubstitutes` attribute in derivations to be ignored, and for substituters to always be used. This option should be a good middle-ground, since it doesn't imply rebuilding the world, such as the approach I took in - https://github.com/NixOS/nixpkgs/pull/221048 See Also: - https://github.com/NixOS/nix/issues/4442 # Context This is extremely valuable for users of Nix in CI, where usually `nix-build-uncached` is used. There, derivations which disallow substitutes cause headaches as the inputs for building already-cached derivations need to be fetched to spuriously rebuild some simple text file. # Checklist for maintainers Maintainers: tick if completed or explain if not relevant - [ ] agreed on idea - [ ] agreed on implementation strategy - [ ] tests, as appropriate - functional tests - `tests/**.sh` - unit tests - `src/*/tests` - integration tests - `tests/nixos/*` - [ ] documentation in the manual - [ ] code and comments are self-explanatory - [ ] commit message explains why the change was made - [ ] new feature or incompatible change: updated release notes # Priorities Add :+1: to [pull requests you find important](https://github.com/NixOS/nix/pulls?q=is%3Aopen+sort%3Areactions-%2B1-desc).