How to use cache from cuda-maintainers

The cuda-maintainers team has a binary cache: Cachix - Nix binary cache hosting

I guess they don’t build binaries for each and every nixpkgs commit. Does someone know how to find out which nixpkgs commits have binaries in the cache? I would then try to use only those commits in a shell.nix.

Hi! The build history is currently available at Hercules CI. Each “job” links to a github commit that contains a flake.lock file pinning the nixpkgs revisions built

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I’m not sure how to read some of the Info:

In the Hercules CI Job overview, all jobs seem to be tagged with a branch name. So far I encountered the tags flake-update, master and nixos-unstable.

Looking at the nixpkgs-cuda-ci repo on Github, it has three branches: develop, flake-update and gh-pages. The nixpkgs repo has no flake-update branch, but it has master and nixos-unstable. It seems like the tag of the CI jobs can refer to either a nixpkgs-cuda-ci branch, or a nixpkgs branch. I guess when the tag is of master or unstable it refers to the nixpkgs branch used, and in case of flake-update nixpkgs was not involved so it refers to the nixpkgs-cuda-ci branch. Is that correct?

I have looked for the latest successful job with master branch, no overlays, and all GPU architectures and found job 4616. In the “source” field this links to a nixpkgs-cuda-ci commit. I opened the respective flake.lock. It has the key nodes.nixpkgs, but also nodes.nixpkgs-master, and some more nodes.nixpkgs-.... I guess I have to look only at nodes.nixpkgs, right?

The job links to this commit: 5d7ef35983f7ba063d941922de7ef73665d6a053.
Looking at its inputs:

❯ nix flake metadata github:SomeoneSerge/nixpkgs-cuda-ci/5d7ef35983f7ba063d941922de7ef73665d6a053
├───nixpkgs follows input 'nixpkgs-master'
├───nixpkgs-master: github:NixOS/nixpkgs/285aa1f48e62932fed2089ddb04768172ae4a625

…the pinned master was pointing at 285aa1f48e62932fed2089ddb04768172ae4a625

(I know, it’s currently a mess)

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