fix(e2e): report signaled host server startups

scripts/e2e/parallels/host-server.ts

@@ -151,11 +151,11 @@ async function waitForHostServer(
   });
   const startedAt = Date.now();
   while (Date.now() - startedAt < 10_000) {
-    if (child.exitCode != null) {
+    if (hasHostServerChildExited(child)) {
       if (!childClosed) {
         await Promise.race([childClose, delay(HOST_SERVER_STDERR_DRAIN_MS)]);
       }
-      die(`host artifact server exited early: ${stderr.trim() || `exit ${child.exitCode}`}`);
+      die(`host artifact server exited early: ${stderr.trim() || formatHostServerExit(child)}`);
     }
     if (await canConnect(port)) {
       return;
@@ -176,6 +176,10 @@ function appendBoundedOutput(previous: string, chunk: Buffer, limitBytes: number
   return combined.subarray(combined.byteLength - limitBytes).toString("utf8");
 }
 
+function formatHostServerExit(child: ChildProcessWithoutNullStreams): string {
+  return child.signalCode ? `signal ${child.signalCode}` : `exit ${child.exitCode ?? "unknown"}`;
+}
+
 async function canConnect(port: number): Promise<boolean> {
   return await new Promise((resolve) => {
     const socket = createConnection({ host: "127.0.0.1", port });

test/scripts/parallels-smoke-model.test.ts

@@ -557,6 +557,42 @@ exit 42
     },
   );
 
+  it.runIf(process.platform !== "win32")(
+    "reports signaled host artifact server startup exits immediately",
+    async () => {
+      const tempDir = mkdtempSync(join(tmpdir(), "openclaw-parallels-host-server-signal-"));
+      const fakePython = join(tempDir, "python3");
+      writeFileSync(
+        fakePython,
+        `#!/usr/bin/env bash
+kill -TERM "$$"
+`,
+      );
+      chmodSync(fakePython, 0o755);
+
+      try {
+        const port = await unusedLoopbackPort();
+        const result = spawnNodeEvalSync(
+          `import { startHostServer } from "./${TS_PATHS.hostServer}"; await startHostServer({ dir: ".", hostIp: "127.0.0.1", port: ${port}, artifactPath: "artifact.tgz", label: "artifact" });`,
+          {
+            env: {
+              ...process.env,
+              PATH: `${tempDir}${delimiter}${process.env.PATH ?? ""}`,
+            },
+            imports: ["tsx"],
+            maxBuffer: 1024 * 1024,
+          },
+        );
+
+        expect(result.status).toBe(1);
+        expect(result.stderr).toContain("host artifact server exited early: signal SIGTERM");
+        expect(result.stderr).not.toContain("did not start");
+      } finally {
+        rmSync(tempDir, { force: true, recursive: true });
+      }
+    },
+  );
+
   it("quotes shell args and resolves fuzzy snapshot hints through the shared TypeScript helper", () => {
     const tempDir = mkdtempSync(join(tmpdir(), "openclaw-parallels-helper-"));
     writeFakePrlctl(