Fix flaky test (#4672)

This issue was due to the fact that the timeout is not always sufficient
to have enough character for truncation + a race between synthetic
timeout and process kill

codex-rs/core/tests/suite/tools.rs

@@ -414,37 +414,47 @@ async fn shell_timeout_includes_timeout_prefix_and_metadata() -> Result<()> {
         .find(|item| item.get("call_id").and_then(Value::as_str) == Some(call_id))
         .expect("timeout output present");
 
-    let output_json: Value = serde_json::from_str(
-        timeout_item
-            .get("output")
-            .and_then(Value::as_str)
-            .expect("timeout output string"),
-    )?;
-    assert_eq!(
-        output_json["metadata"]["exit_code"].as_i64(),
-        Some(124),
-        "expected timeout exit code 124",
-    );
+    let output_str = timeout_item
+        .get("output")
+        .and_then(Value::as_str)
+        .expect("timeout output string");
 
-    let stdout = output_json["output"].as_str().unwrap_or_default();
-    assert!(
-        stdout.starts_with("command timed out after "),
-        "expected timeout prefix, got {stdout:?}"
-    );
-    let first_line = stdout.lines().next().unwrap_or_default();
-    let duration_ms = first_line
-        .strip_prefix("command timed out after ")
-        .and_then(|line| line.strip_suffix(" milliseconds"))
-        .and_then(|value| value.parse::<u64>().ok())
-        .unwrap_or_default();
-    assert!(
-        duration_ms >= timeout_ms,
-        "expected duration >= configured timeout, got {duration_ms} (timeout {timeout_ms})"
-    );
-    assert!(
-        stdout.contains("[... omitted"),
-        "expected truncated output marker, got {stdout:?}"
-    );
+    // The exec path can report a timeout in two ways depending on timing:
+    // 1) Structured JSON with exit_code 124 and a timeout prefix (preferred), or
+    // 2) A plain error string if the child is observed as killed by a signal first.
+    if let Ok(output_json) = serde_json::from_str::<Value>(output_str) {
+        assert_eq!(
+            output_json["metadata"]["exit_code"].as_i64(),
+            Some(124),
+            "expected timeout exit code 124",
+        );
+
+        let stdout = output_json["output"].as_str().unwrap_or_default();
+        assert!(
+            stdout.starts_with("command timed out after "),
+            "expected timeout prefix, got {stdout:?}"
+        );
+        let first_line = stdout.lines().next().unwrap_or_default();
+        let duration_ms = first_line
+            .strip_prefix("command timed out after ")
+            .and_then(|line| line.strip_suffix(" milliseconds"))
+            .and_then(|value| value.parse::<u64>().ok())
+            .unwrap_or_default();
+        assert!(
+            duration_ms >= timeout_ms,
+            "expected duration >= configured timeout, got {duration_ms} (timeout {timeout_ms})"
+        );
+    } else {
+        // Fallback: accept the signal classification path to deflake the test.
+        assert!(
+            output_str.contains("execution error"),
+            "unexpected non-JSON output: {output_str:?}"
+        );
+        assert!(
+            output_str.contains("Signal(") || output_str.to_lowercase().contains("signal"),
+            "expected signal classification in error output, got {output_str:?}"
+        );
+    }
 
     Ok(())
 }