The hosted runner: GitHub Actions 187 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.

Unexpected input(s) 'build-flags', valid inputs are ['add-hosts', 'allow', 'annotations', 'attests', 'build-args', 'build-contexts', 'builder', 'cache-from', 'cache-to', 'call', 'cgroup-parent', 'context', 'file', 'labels', 'load', 'network', 'no-cache', 'no-cache-filters', 'outputs', 'platforms', 'provenance', 'pull', 'push', 'sbom', 'secrets', 'secret-envs', 'secret-files', 'shm-size', 'ssh', 'tags', 'target', 'ulimit', 'github-token']