fix: Check for stderr error in receive() (#2905)

crates/mcp-client/examples/integration_test.rs

@@ -22,6 +22,17 @@ async fn main() -> Result<()> {
     test_transport(sse_transport().await?).await?;
     test_transport(stdio_transport().await?).await?;
 
+    // Test broken transport
+    match test_transport(broken_stdio_transport().await?).await {
+        Ok(_) => assert!(false, "Expected an error but got success"),
+        Err(e) => {
+            assert!(e
+                .to_string()
+                .contains("error: package(s) `thispackagedoesnotexist` not found in workspace"));
+            println!("Expected error occurred: {e}");
+        }
+    }
+
     Ok(())
 }
 
@@ -52,6 +63,17 @@ async fn stdio_transport() -> Result<StdioTransport> {
     ))
 }
 
+async fn broken_stdio_transport() -> Result<StdioTransport> {
+    Ok(StdioTransport::new(
+        "cargo",
+        vec!["run", "-p", "thispackagedoesnotexist"]
+            .into_iter()
+            .map(|s| s.to_string())
+            .collect(),
+        HashMap::new(),
+    ))
+}
+
 async fn test_transport<T>(transport: T) -> Result<()>
 where
     T: Transport + Send + 'static,