There are patterns to address it such as creating your own Result type alias with the error type parameter (E) fixed to an error type you own:

    type Result<T> = result::Result<T, MyError>;

    #[derive(Debug)]
    enum MyError {
        IOError(String)
        // ...
    }

Your owned (i.e. not third-party) Error type is a sum type of error types that might be thrown by other libraries, with a newtype wrapper (`IOError`) on top.

Then implement the `From` trait to map errors from third-party libraries to your own custom Error space:

    impl From<io::Error> for MyError {
        fn from(e: io::Error) -> MyError {
            MyError::IOError(e.to_string())
        }
    }

Now you can convert any result into a single type that you control by transforming the errors:

    return sender
        .write_all(msg.as_bytes())
        .map_err(|e| e.into());

There is a little boilerplate and mapping between error spaces that is required but I don't find it that onerous.