fix(ports): specify IPv4 loopback host in ensurePortAvailable

ajwan8998 · claude · ajwan8998 · commit 789d59f5a5d7 · 2026-06-18T11:13:59.000+08:00
ensurePortAvailable uses net.listen({ port }) without specifying host. On dual-stack machines, this binds to the IPv6 wildcard '::', so an IPv4-only occupant of 127.0.0.1 is not detected and the pre-flight erroneously reports the port as free. Add host: '127.0.0.1'. Closes: #94379 Co-Authored-By: Claude <noreply@anthropic.com>
diff --git a/src/infra/ports.ts b/src/infra/ports.ts
@@ -39,7 +39,7 @@ export async function describePortOwner(port: number): Promise<string | undefine
 export async function ensurePortAvailable(port: number): Promise<void> {
   // Detect EADDRINUSE early with a friendly message.
   try {
-    await tryListenOnPort({ port });
+    await tryListenOnPort({ port, host: "127.0.0.1" });
   } catch (err) {
     if (isErrno(err) && err.code === "EADDRINUSE") {
       throw new PortInUseError(port);
