hashicorp/nomad · error

post-run hook %q failed: %w

Error message

post-run hook %q failed: %w

What it means

During alloc shutdown, each post-run hook's Postrun() is executed and any error is accumulated into a multierror wrapped as "post-run hook \"<name>\" failed: <cause>". This indicates cleanup (e.g. directory cleanup, network teardown) failed while stopping the allocation.

Source

Thrown at client/allocrunner/alloc_runner_hooks.go:286

		}()
	}

	var merr multierror.Error
	for _, hook := range ar.runnerHooks {
		post, ok := hook.(interfaces.RunnerPostrunHook)
		if !ok {
			continue
		}

		name := post.Name()
		var start time.Time
		if ar.logger.IsTrace() {
			start = time.Now()
			ar.logger.Trace("running post-run hook", "name", name, "start", start)
		}

		if err := post.Postrun(); err != nil {
			merr.Errors = append(merr.Errors, fmt.Errorf("post-run hook %q failed: %w", name, err))
		}

		if ar.logger.IsTrace() {
			end := time.Now()
			ar.logger.Trace("finished post-run hooks", "name", name, "end", end, "duration", end.Sub(start))
		}
	}

	return helper.FlattenMultierror(merr.ErrorOrNil())
}

// destroy is used to run the runners destroy hooks. All hooks are run and
// errors are returned as a multierror.
func (ar *allocRunner) destroy() error {
	if ar.logger.IsTrace() {
		start := time.Now()
		ar.logger.Trace("running destroy hooks", "start", start)
		defer func() {

View on GitHub (pinned to 482b49bf1a)

Solutions

1. Identify the failing hook from the message and the wrapped cause
2. Check for leftover processes holding files/mounts in the alloc directory (lsof/grep mounts) and kill them
3. Manually clean stale alloc dirs under the client data_dir if safe, and verify client disk/permissions
4. Check CNI plugin health if the failure is network teardown; upgrade/fix plugins and garbage-collect (nomad system gc)

if err := stopAlloc(allocID); err != nil {
  if strings.Contains(err.Error(), "post-run hook") {
    // cleanup failed: inspect alloc dir mounts and CNI, then garbage collect
    nomadSystemGC()
  }
}

When it happens

Trigger: Run() → postrun after task runners stop; any hook with Postrun() errors, e.g. alloc dir cleanup hook failing to remove directories or network isolation teardown failing.

Common situations: Files inside alloc_dir held open or mounted (won't unmount/remove) by leftover processes; permission errors on cleanup; CNI network teardown failure; disk I/O errors on the client host.

Related errors

• pre-run hook %q failed: %v
• update hook %q failed: %v
• no servers
• missing node ID
• plugin in use

AI-assisted analysis of hashicorp/nomad@482b49bf1a (2026-09-04). Data as JSON: /api/errors/baff4157020266b7. Report an issue: GitHub.