include issue link in reported error

Author: gstvg

datafusion/physical-expr/src/expressions/lambda.rs

@@ -224,8 +224,9 @@ fn check_async_udf(body: &Arc<dyn PhysicalExpr>) -> Result<()> {
             .downcast_ref::<ScalarFunctionExpr>()
             .is_some_and(|udf| udf.fun().as_async().is_some()))
     })? {
-        // https://github.com/apache/datafusion/issues/22091
-        return plan_err!("Async functions in lambdas aren't supported");
+        return plan_err!(
+            "Async functions in lambdas aren't supported, see https://github.com/apache/datafusion/issues/22091"
+        );
     }
 
     Ok(())

datafusion/sqllogictest/test_files/async_udf.slt

@@ -104,4 +104,4 @@ physical_plan
 query error
 select array_transform([1], v -> async_abs(v));
 ----
-DataFusion error: Error during planning: Async functions in lambdas aren't supported
+DataFusion error: Error during planning: Async functions in lambdas aren't supported, see https://github.com/apache/datafusion/issues/22091