The Linux pipeline deploys via hydraskin launch/update, which needs hydraskin >= v0.12.0. Only a few nodes were updated by hand (pi-node-001, pi-node-004, hydraskin-arm-1); the rest of the hydraskin fleet is older and cannot be a deploy target. Roll v0.12.0 fleet-wide. This is gated by #515 (hydracluster does not ship recipes with the binary, so auto-provisioning a hydraskin node currently no-ops); fix #515 first, then a fleet hydraskin release + reprovision. Related: #508, #515.