argunix pre-flight: no connected builder satisfies this derivation's
requiredSystemFeatures. Failing fast instead of waiting for nix's
remote-build scheduler to give up.

attribute: checks.x86_64-linux.zot-referrers
derivation: /nix/store/27nxz6gg071ni8rms4qsmwqk76hiyi1p-vm-test-run-zot-referrers.drv
required (system, features): (x86_64-linux, ["kvm", "nixos-test"])

connected builders:
  - argunixdev: systems=["x86_64-linux", "aarch64-linux", "i686-linux"] features=["benchmark", "big-parallel", "nixos-test"] max_jobs=2 state=Active

Fix one of:
  1. Add the missing feature(s) to a builder's nix.settings.system-features.
  2. Add a builder host that natively satisfies the feature.
  3. Drop the requirement from the derivation if it isn't actually needed.

Note on kvm: option 1 will not help if /dev/kvm is absent. NixOS
lists kvm in system-features unconditionally, but the agent checks
the device before advertising it, so the claim is dropped again on
reconnect.