Ability to return custom errors

[CowBoy4mH3LL]

Say I have a custom error SError{message:String} and I implement From<std:io:Error> on it. Now, from a function, say, fn(&self) -> Result<(),SError> in an rtc::remote labelled trait, I get an std:io:error as a result of calling await on some other async function. Even if I have implemented the From cast from Error to SError, it does not seem to be able to cast between the output Result forms. Any idea why?