error.Error.is_transient

true means this error proves that the requested mutation did not run, or came from an operation that only reads state. The condition may need to clear first: capacity can become available, a client can resume, a resource-limited spawn can be retried, or a server can answer again.

false does not mean that the handle is unusable. A subprocess timeout, output-reader failure, child-wait failure, or lost supervisor can leave the executor ready for another call, but tmux may already have carried out the first one. Replaying a mutation could duplicate its effect. A shut down executor and a closed or timed-out control connection are also false because they require a new server or connection.