Hydra missing store path when built on buildMachine

Anyone know how to get hydra to copy build outputs to hydra’s /nix/store from a build machine? Seems like it doesn’t happen by default unless I’m missing something. Just using nix-ssh to serve the cache for now.

when a build is done on a build machine, I see only two files on hydra-server: /var/lib/hydra/cache/hks67kr0wvd5kl9hk8yinmnkx6lviapi.narinfo and /nix/var/nix/gcroots/hydra/hks67kr0wvd5kl9hk8yinmnkx6lviapi-python3.7-mlflow-1.4.0 . Nothing in /nix/store

only clue I get from journalctl is hydra-queue-runner[2163]: copying path '/nix/store/hks67kr0wvd5kl9hk8yinmnkx6lviapi-python3.7-mlflow-1.4.0' (60848440 bytes, compressed 0.0% in 39 ms) to binary cache , and yet I see nothing in store. Plenty of space on disk drive


I’m confused, and I don’t think you’re using the tooling as intended.

You can use nix-copy-closure to copy a package and all of it’s dependencies to a target machine

Entirely possible I’m confused. I’m trying to use hydra to populate a binary cache. I thought that setting the store-uri also set the location of the binary cache. Unlike hydra.nixos.org, I have that set to file:///var/lib/hydra/cache rather than S3. From the logs, it does appear that hydra-queue-runner copies the build output to the cache, but I don’t see the files

if you’re using your own personal instance, then that’s way out of my league :(. sorry