The hosted runner: GitHub Actions 2 lost communication with the server. Anything in your workflow that terminates the runner process, starves it for CPU/Memory, or blocks its network access can cause this error.

the remote end hung up unexpectedly

RPC failed; HTTP 503 curl 22 The requested URL returned error: 503

expected 'packfile'

ubuntu-latest pipelines will use ubuntu-24.04 soon. For more details, see https://github.com/actions/runner-images/issues/10636