`ob run` suddently stopped working due to HTTP error 500

[abigailalice]

So running ob run --verbose this morning gave me this error:

Starting Obelisk </nix/store/5qhw99ipn683vik513frrqraz8c3p07j-obelisk-command-0.9.0.1/bin/.ob-wrapped> args=["run","--verbose"] logging-level=Debug
Thunk specification git-v7 did not match "./.obelisk/impl": ReadThunkError_UnrecognizedPaths ("./.obelisk/impl/github.json" :| [])
Thunk specification github-v8 matched "./.obelisk/impl"
./.obelisk/impl: command not cached, building ...
Creating process: nix-build ./.obelisk/impl -A command --out-link ./.obelisk/impl/.attr-cache/command.out
warning: error: unable to download 'https://cache.iog.io/b18xzkcdx27mkwszrsmsj5nk7ghjaxp7.narinfo': HTTP error 500; retrying in 345 ms
warning: error: unable to download 'https://cache.iog.io/b18xzkcdx27mkwszrsmsj5nk7ghjaxp7.narinfo': HTTP error 500; retrying in 624 ms
warning: error: unable to download 'https://cache.iog.io/b18xzkcdx27mkwszrsmsj5nk7ghjaxp7.narinfo': HTTP error 500; retrying in 1190 ms
warning: error: unable to download 'https://cache.iog.io/b18xzkcdx27mkwszrsmsj5nk7ghjaxp7.narinfo': HTTP error 500; retrying in 2027 ms
error: unable to download 'https://cache.iog.io/b18xzkcdx27mkwszrsmsj5nk7ghjaxp7.narinfo': HTTP error 500
(use '--show-trace' to show detailed location information)
Process exited with code 1; nix-build ./.obelisk/impl -A command --out-link ./.obelisk/impl/.attr-cache/command.out
✖ Running nix-build on ./.obelisk/impl [command]

Everything was working perfectly fine last night, so I'm curious if there's any way to fix this, or if I just need to wait until something on cache.iog.io is fixed. I've been working on this project for a while, and it didn't even occur to me ob run would even require internet access to complete, but maybe it does. I'm kind of unfamiliar with nix, so I'm not sure if I'm even understanding how nix caches actually work correctly, but the possibility of things just stopping to work overnight makes me a little nervous; if it's just to speed things up the lack of an automatic fallback seems odd. If there's anyway to build whatever needs to be done on my system rather than downloading a cached version that would be handy.

[alexfmpe]

./.obelisk/impl: command not cached, building ...

suggests something wasn't already present in the nix store. Could be there was some change on your project or maybe some nix-collect-garbage was run. Do you have automatic gc setup on nix?

You could try nix-build -A ghc.obelisk-command --fallback or possibly nix-build -A exe --fallback to force the build to be done locally without getting tripped by offline caches.

the possibility of things just stopping to work overnight makes me a little nervous

Offline caches are more of a pain than they need to be. I think it got better in newer nix though? Maybe obelisk is still pinning an old one?
If all else fails, last resort is temporarily disabling that cache in your config ( might need to rebuild or restart nix daemon depending on how you set up nix)