Nixops won't fallback to second binary cache if first one is broken

[LisannaAtHome]

Nixops is not falling back to my second binary cache (cache.nixos.org) if the first one I have specified is broken (returning error 500). This is useless, since it blocks my ability to deploy to fix the binary cache in the first place.

Workaround: temporarily remove the offending binary cache from your substituters list (e.g., by passing --option substituters https://cache.nixos.org)

[roberth]

This appears to be a Nix issue. Nix has behavior that disables caches when they're down now. It may not be perfect yet though.