Error message
In the message, %s marks a value that the engine fills in when it raises the error.
The story
Rush refused to start, because this machine has no usable machine id. Let's see why that matters. Every being that rush creates carries a node id, and that id is derived from exactly two things: the machine id file at slash etc slash machine dash id, and your user. Nothing else. There is no fallback, no random id, no per-user file made on the side. Why so strict? Because an id that changes between runs, or that is invented on the fly, would break identity: the same machine would look like a different one every time. So if the file is missing, empty, or unreadable, the engine is not born, and rush says so on the screen and exits with code one. The fix belongs to the machine, not to rush. On a normal Linux system, run systemd machine id setup, or dbus uuidgen with the ensure flag. In a container, mount the host's machine id file, read only. The first slot says what is wrong with the file, and the second explains why rush will not work around it. Fix the machine, and rush starts.
Text from the Rush engine's error catalogue.