Failed to execute `yarn gsn-with-ganache`

[felicityin]

$ yarn gsn-with-ganache
...
Setting minimum stake of 1 TestWeth on Hub
Setting minimum stake of 0.000000000000000001 wEth
Naive Paymaster successfully funded, balance: 1
Registering GSN relayer at http://127.0.0.1:35287
Error: Request failed with status code 503
    at createError (/home/aping/git/workshop/node_modules/axios/lib/core/createError.js:16:15)
    at settle (/home/aping/git/workshop/node_modules/axios/lib/core/settle.js:17:12)
    at IncomingMessage.handleStreamEnd (/home/aping/git/workshop/node_modules/axios/lib/adapters/http.js:269:11)
    at IncomingMessage.emit (node:events:525:35)
    at endReadableNT (node:internal/streams/readable:1359:12)
    at processTicksAndRejections (node:internal/process/task_queues:82:21) {
  config: {
    url: 'http://127.0.0.1:35287/getaddr',
    method: 'get',
    headers: {
      Accept: 'application/json, text/plain, */*',
      'Content-Type': 'application/json',
      'User-Agent': 'axios/0.21.4',
      host: '127.0.0.1:35287'