nix-community cache questions -- missing narinfo? in recent builds of blender

[d-r-a-b]

Is there something wrong with the nix-community Hydra instance for cudaSupport and/or my understanding of how it should work? It seems that a missing .narinfo file on recent blender builds is killing the substitution for me.

I recently did a nixos-rebuild --upgrade switch and found that it was suddenly building blender instead of downloading a cache from the nix-community cachix (as setup per the docs at https://discourse.nixos.org/t/cuda-cache-for-nix-community/56038). I was previously pulling in blender from the binary cache just fine. So I did some digging and have currently gone as far as I can.

The most recent blender build is from nixpkgs 36bd116f1115, so I figured that by doing a nixos-rebuild against that commit, I should be able to hit the cache and download instead of build. Running nixos-rebuild dry-run against 36bd116f1115 confirms that it does want to build /nix/store/q3hq93qfapbga47xb7gnp04q59pl0vpw-blender-4.5.1.drv. So far so good, as that matches the successful hydra build. However, nixos-rebuild cannot grab it according to nixos-rebuild -v --option narinfo-cache-negative-ttl 0 test because it fails to download the .narinfo:

these 13 derivations will be built:
  /nix/store/q3hq93qfapbga47xb7gnp04q59pl0vpw-blender-4.5.1.drv
  /nix/store/… [omitted for brevity]
querying info about ‘/nix/store/zp4ar77zpcdhy6ljajxwirg5l760f1qj-blender-4.5.1’ on ‘https://cache.nixos.org’…
downloading ‘https://cache.nixos.org/zp4ar77zpcdhy6ljajxwirg5l760f1qj.narinfo’…
querying info about ‘/nix/store/zp4ar77zpcdhy6ljajxwirg5l760f1qj-blender-4.5.1’ on ‘https://nix-community.cachix.org’…
downloading ‘https://nix-community.cachix.org/zp4ar77zpcdhy6ljajxwirg5l760f1qj.narinfo’…
querying info about ‘/nix/store/zp4ar77zpcdhy6ljajxwirg5l760f1qj-blender-4.5.1’ on ‘https://cache.nixos.org’…
downloading ‘https://cache.nixos.org/zp4ar77zpcdhy6ljajxwirg5l760f1qj.narinfo’…
querying info about ‘/nix/store/zp4ar77zpcdhy6ljajxwirg5l760f1qj-blender-4.5.1’ on ‘https://nix-community.cachix.org’…
downloading ‘https://nix-community.cachix.org/zp4ar77zpcdhy6ljajxwirg5l760f1qj.narinfo’…

Indeed, attempting to download https://nix-community.cachix.org/zp4ar77zpcdhy6ljajxwirg5l760f1qj.narinfo results in a 404 NOT FOUND, which is quite surprising because https://hydra.nix-community.org/build/7018318 shows that this derivation has been successfully built.

Just a few days ago (https://hydra.nix-community.org/build/6932767), Narinfos were being generated fine. /nix/store/va2lri06wq6rrqsifvfj8w3fd49kfmg9-blender-4.5.1.drv was realized to /nix/store/gpway5bq1w4kyil4awnblrhjhfmbllqn-blender-4.5.1 and http://nix-community.cachix.org/gpway5bq1w4kyil4awnblrhjhfmbllqn.narinfo downloads perfectly fine, which then allows nixos-rebuild to grab it.

I see that I can curl https://hydra.nix-community.org/build/7018318/nix/closure/blender-4.5.1.closure.gz | gunzip | nix-store --import to at least get the blender built against nixpkgs 36bd116f1115, but I'm still not clear on why the narinfo was missing from this build.

Am I missing something? I am new to NixOS, so it's very possible I'm messing something up, and I would love to know if I should be doing something else or if there's a better way to troubleshoot this.

EDIT: previous version of this post had another issue that I realized was user error.

[zowoq]

I think this may have just been a glitch, I've re-pushed blender to the cache.

[d-r-a-b]

Amazing, thank you! I confirm I can see https://nix-community.cachix.org/gpway5bq1w4kyil4awnblrhjhfmbllqn.narinfo for the current nixos-unstable-small. Would you be able to do the same for https://hydra.nix-community.org/build/7016091 which should produce http://nix-community.cachix.org/vf10ic31dblxnl39vgx34kwjqyal2vs3.narinfo to prevent cache-misses for the current nixos-unstable? Thank you again!

[zowoq]

Would you be able to do the same for https://hydra.nix-community.org/build/7016091

Done.