@@ -14,6 +14,8 @@ if (import.meta.main) {
   const log = getLogger(["corbits-builder", "hub"]);
   let close = async () => {};
   let stopping: Promise<void> | undefined;
+  let stopRequested = false;
+  let startupDone = false;
   const shutDown = async () => {
     for (const step of [close, dispose]) {
       try {
@@ -28,6 +30,7 @@ if (import.meta.main) {
   const exitOnFatal = (message: string) => async (error: unknown) => {
     try {
       log.error(message, errorMetadata(error));
+      // Unlike a signal, this does not wait for startup: a startup stuck on the failure would keep the hub up instead of letting its supervisor restart it.
       await stop();
     } finally {
       // Handles a failed shutdown left open would keep a broken hub alive instead of letting its supervisor restart it.
@@ -39,14 +42,18 @@ if (import.meta.main) {
     exitOnFatal("Hub hit an unhandled rejection"),
   );
   process.on("uncaughtException", exitOnFatal("Hub hit an uncaught exception"));
-  process.once("SIGTERM", () => {
-    void stop();
-  });
-  process.once("SIGINT", () => {
-    void stop();
-  });
-  try {
+  // Startup takes seconds; a stop meanwhile is recorded and acted on when startup finishes, so it closes what startup opened.
+  const requestStop = () => {
+    stopRequested = true;
+    if (startupDone) void stop();
+  };
+  process.once("SIGTERM", requestStop);
+  process.once("SIGINT", requestStop);
+  const start = async () => {
     const runtime = await createHubRuntime();
+    close = () => runtime.close();
+    // A stop requested meanwhile must not open the port; the stop after startup closes the runtime.
+    if (stopRequested) return;
     const server = Bun.serve({
       hostname: runtime.hostname,
       port: runtime.port,
@@ -63,6 +70,9 @@ if (import.meta.main) {
     log.info(
       "Hub ready: Postgres connected; local Interchange sidecar provisioner",
     );
+  };
+  try {
+    await start();
   } catch (error) {
     log.error(
       "Hub startup failed; check environment and database readiness",
@@ -71,4 +81,6 @@ if (import.meta.main) {
     process.exitCode = 1;
     await stop();
   }
+  startupDone = true;
+  if (stopRequested) await stop();
 }