doc endpoint returns 500 with no errors in logs

const app = new OpenAPIHono<{ Bindings: Bindings }>();
app.use("*", cors());
app.get("/v2/hello", async (c) => {
  return c.json({ message: "Hello, World!" });
});
...
  app.openapi(
    createRoute({
      method: apiConfig.method,
      path: `/v2${apiConfig.path}`,
      responses: schema ? {
        200: {
          description: "Successful response",
          content: {
            "application/json": {
              schema: schema
            },
          },
        },
      } : null,
    }),
    async (c) => {
      console.log("Hello Hono!");
      const resp = await config.handlerFunc(c.env.event, c.env.lambdaContext);
      console.log("resp", resp);
      return c.json(resp);
    },
  );
...
app.doc("/v2/doc", { info: { title: "My API", version: "v2" }, openapi: "3.1.0"});
app.get('/v2/swagger', swaggerUI({url: '/v2/doc'}));

const app = new OpenAPIHono<{ Bindings: Bindings }>();
app.use("*", cors());
app.get("/v2/hello", async (c) => {
  return c.json({ message: "Hello, World!" });
});
...
  app.openapi(
    createRoute({
      method: apiConfig.method,
      path: `/v2${apiConfig.path}`,
      responses: schema ? {
        200: {
          description: "Successful response",
          content: {
            "application/json": {
              schema: schema
            },
          },
        },
      } : null,
    }),
    async (c) => {
      console.log("Hello Hono!");
      const resp = await config.handlerFunc(c.env.event, c.env.lambdaContext);
      console.log("resp", resp);
      return c.json(resp);
    },
  );
...
app.doc("/v2/doc", { info: { title: "My API", version: "v2" }, openapi: "3.1.0"});
app.get('/v2/swagger', swaggerUI({url: '/v2/doc'}));