Require GeneralError to be Send
GeneralError error content  must be Send, as it will be passed
along channels.
@@ -31,7 +31,7 @@ pub enum ExecutionAdapterError {
/// to the `ExecutionAdapter`.
RoutingError(Box<TransactionPair>),
- GeneralExecutionError(Box<dyn Error>),
+ GeneralExecutionError(Box<dyn Error + Send>),
}
impl Error for ExecutionAdapterError {
