SandboxUnavailableError

Run commands and agent-written programs inside an operating-system boundary. See the guide.

class zett_agent.sandbox.errors.SandboxUnavailableError

The requested sandbox cannot run on this machine.

The message says why and, where a fix exists, what to install or change. The sandbox layer never answers this by running the command unsandboxed: the caller chooses PassthroughSandbox explicitly, or fixes the machine.