Created Started Cancelled
By: Tom Sydney Kerckhove <syd@cs-syd.eu>
Fill and read the NixCI cache from local builds NixCI rebuilds from scratch what a contributor has already built, which is most of what it charges us for: the same derivations are built here first, they just never leave this machine. The dev shell now points Nix at a post-build-hook that copies every path it builds to the NixCI cache, and the flake substitutes from that cache in return. Both directions only need a token in ~/.netrc, so no system configuration is involved: Nix hands the daemon its own netrc-file setting, and the hook, which runs as the daemon user, reads the token through it. A machine with no token, or no network, keeps building as before, because a post-build-hook that fails fails the build it was called for.