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Setting Up Binary Cache

Building Spectrum from source can take a very long time. To avoid having to wait when building the system to try it out or test patches, an x86_64 binary cache service is available. If configured to do so, Nix will download build outputs from the cache, instead of building them locally.

The binary cache is populated by doing a Spectrum release build, on the latest NixOS unstable, on Vultr, and are signed to ensure authenticity. The build infrastructure and signing key are accessible by Alyssa Ross and Puck Meerburg. Storage is provided by Daniel Kuehn. Please get in touch if you encounter any trouble with it.

For NixOS

Add the following configuration to /etc/nixos/configuration.nix:

{ ... }:

  nix.settings.substituters = [ "" ];
  nix.settings.trusted-public-keys = [

This configuration adds the Spectrum binary cache as a substituter and makes Nix trust builds signed with its public key.

To apply changes, rebuild your system with the nixos-rebuild command.

For Non-NixOS Systems

Add the following configuration to /etc/nix/nix.conf:

substituters =
trusted-public-keys =

Run systemctl restart nix-daemon.service after making any changes in the Nix configuration. After that the binary cache will be used automatically when nix-build is run.

If you have other binary caches configured besides, make sure to add the Spectrum cache URL and public key to the existing configuration lines in your nix.conf file.