`nix flake check --store` not working

[yajo]

Describe the bug

nix flake check behaves very different with remote store than nix build commands.

Steps To Reproduce

Create this example flake:

{
  description = "A flake with a check that always fails";

  outputs = {nixpkgs, ...}: let
    forAllSystems = nixpkgs.lib.genAttrs ["x86_64-linux" "aarch64-linux"];
  in {
    checks = forAllSystems (system: let
      pkgs = nixpkgs.legacyPackages.${system};
    in {
      default = pkgs.runCommand "failing-check" {} ''
        exit 1
      '';
    });
  };
}

Checking with remote store just hangs: nix flake check --store ssh-ng://eu.nixbuild.net

Adding local eval does not trigger builds: nix flake check --store ssh-ng://eu.nixbuild.net --eval-store auto

Local eval and store triggers builds as expected: nix flake check

Using the equivalent nix build commands trigger builds as expected:

• nix build --store ssh-ng://eu.nixbuild.net .#checks.x86_64-linux.default
• nix build --store ssh-ng://eu.nixbuild.net --eval-store auto .#checks.x86_64-linux.default

Expected behavior

Builds for supported arch(es) should be triggered with nix flake check always, unless --no-build is explicitly passed.

Metadata

nix-env (Nix) 2.34.7

Additional context

I'm trying to use nixbuild's remote store solution for fast CI.

I'd love to be able to just use this command on my CI:

nix flake check --all-systems --store ssh-ng://eu.nixbuild.net --eval-store auto --builders ''

Checklist

• checked latest Nix manual (source)
• checked open bug issues and pull requests for possible duplicates

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