Error message
In the message, %s marks a value that the engine fills in when it raises the error.
The story
You asked a holder what it looked like yesterday, and rush answered that it keeps only its present. Here is what happened. In rush you can travel in time with asof, but only where the past was actually saved. A holder that lives in sulfur, the database, keeps every version of everything automatically. A holder that lives on the filesystem is different: it is a directory, and every member is a plain file. When you rewrite a file, the old bytes are gone. When you delete one, it is gone. There is no yesterday on that disk to read. Rush could have returned today's data and called it yesterday's, and you would never know. Instead it refuses, by name, and tells you which holder you asked. Picture a holder called notes on the filesystem, and a query asking for notes as of last week. The answer cannot be true, so rush stops. The fix is in the second slot of the message: if you need history, declare that holder with where sulfur, and from then on every version is kept. If you do not need history, simply drop the asof. Either way, the data stays honest.
Text from the Rush engine's error catalogue.