hashicorp/nomad · error

cannot use signals with env var templates

Error message

cannot use signals with env var templates

What it means

Appended by template validation when change_mode is "signal" and envvars templating is enabled. Signals cannot re-render environment variables of an already-started process, so the combination is invalid.

Source

Thrown at nomad/structs/structs.go:8988

	}

	// Verify the destination doesn't escape
	escaped, err := escapingfs.PathEscapesAllocViaRelative("task", t.DestPath)
	if err != nil {
		mErr.Errors = append(mErr.Errors, fmt.Errorf("invalid destination path: %v", err))
	} else if escaped {
		mErr.Errors = append(mErr.Errors, fmt.Errorf("destination escapes allocation directory"))
	}

	// Verify a proper change mode
	switch t.ChangeMode {
	case TemplateChangeModeNoop, TemplateChangeModeRestart:
	case TemplateChangeModeSignal:
		if t.ChangeSignal == "" {
			_ = multierror.Append(&mErr, fmt.Errorf("Must specify signal value when change mode is signal"))
		}
		if t.Envvars {
			_ = multierror.Append(&mErr, fmt.Errorf("cannot use signals with env var templates"))
		}
	case TemplateChangeModeScript:
		if t.ChangeScript == nil {
			_ = multierror.Append(&mErr, fmt.Errorf("must specify change script configuration value when change mode is script"))
		}

		if err = t.ChangeScript.Validate(); err != nil {
			_ = multierror.Append(&mErr, err)
		}
	default:
		_ = multierror.Append(&mErr, TemplateChangeModeInvalidError)
	}

	// Verify the splay is positive
	if t.Splay < 0 {
		_ = multierror.Append(&mErr, fmt.Errorf("Must specify positive splay value"))
	}

View on GitHub (pinned to 482b49bf1a)

Solutions

1. Remove envvars = true and write the rendered template to a file destination
2. Use change_mode = "restart" or "noop" if you need env-var templates

When it happens

Trigger: Thrown at nomad/structs/structs.go:8988 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of hashicorp/nomad@482b49bf1a (2026-09-04). Data as JSON: /api/errors/5c6768004fdde609. Report an issue: GitHub.