chore: better error variant

src/flow/src/adapter/flownode_impl.rs

@@ -40,7 +40,8 @@ use crate::batching_mode::engine::BatchingEngine;
 use crate::engine::FlowEngine;
 use crate::error::{
     CreateFlowSnafu, ExternalSnafu, FlowNotFoundSnafu, IllegalCheckTaskStateSnafu,
-    InsertIntoFlowSnafu, InternalSnafu, ListFlowsSnafu, SyncCheckTaskSnafu, UnexpectedSnafu,
+    InsertIntoFlowSnafu, InternalSnafu, JoinTaskSnafu, ListFlowsSnafu, SyncCheckTaskSnafu,
+    UnexpectedSnafu,
 };
 use crate::metrics::METRIC_FLOW_TASK_COUNT;
 use crate::repr::{self, DiffRow};
@@ -585,12 +586,7 @@ impl FlowEngine for FlowDualEngine {
                 requests: to_batch_engine,
             })
             .await?;
-        stream_handler.await.map_err(|e| {
-            UnexpectedSnafu {
-                reason: format!("JoinError when handle inserts for flow stream engine: {e:?}"),
-            }
-            .build()
-        })??;
+        stream_handler.await.context(JoinTaskSnafu)??;
 
         Ok(())
     }