fix: fixed release builds

sparse-beacon/src/lib.rs

@@ -147,7 +147,7 @@ where
                         cmd_id
                     ).parse()?,
                     messages::CommandInvocationResult {
-                        result_body: action_result
+                        result_body: serde_json::to_string(&action_result)?
                     }
                 )
                     .await?;