Is there something wrong with nix flake check with remote stores?

[michaelpj]

I'm very uncertain whether this is an issue with nixbuild.net or whether something else is going on. My guess is that it might be nixbuild.net since it could be something to do with your protocol implementation.

I think that sometimes when using nix flake check with a remote store build on nixbuild.net, the checks do not actually get built even if they should do.

Some evidence: in this PR I switched a workflow from using nix flake check to using nix build on an attribute that depended on all the same things. Now it is building some things!

[rickynils]

I think we would need a way to consistently reproduce this issue in order to see if it is Nix or nixbuild.net that does something wrong.