vxcontrol/pentagi · error

failed to get subtask context: %w

Error message

failed to get subtask context: %w

What it means

Returned by flowStatusTool.buildRunningInfo (backend/pkg/tools/flow_manager.go:328) only in verbose mode when the active subtask has a non-empty Context field. The execution context string is run through getDescriptionText, which calls the LLM summarizer when the text exceeds 2*descriptionLimit characters; a summarizer failure is wrapped as 'failed to get subtask context: %w'. This error never occurs in non-verbose mode or when the subtask has no stored context.

Source

Thrown at backend/pkg/tools/flow_manager.go:328

		fmt.Fprintf(sb, "\n=== Active Subtask ===\n")
		fmt.Fprintf(sb, "Subtask ID: %d | Status: %s | Title: %s\n", st.ID, st.Status, st.Title)
		description, err := t.getDescriptionText(ctx, st.Description)
		if err != nil {
			return "", fmt.Errorf("failed to get subtask description: %w", err)
		}
		fmt.Fprintf(sb, "Description:\n%s\n", description)
		if st.Result != "" {
			result, err := t.getResultText(ctx, st.Result)
			if err != nil {
				return "", fmt.Errorf("failed to get subtask result: %w", err)
			}
			fmt.Fprintf(sb, "Result so far:\n%s\n", result)
		}
		if verbose && st.Context != "" {
			execContext, err := t.getDescriptionText(ctx, st.Context)
			if err != nil {
				return "", fmt.Errorf("failed to get subtask context: %w", err)
			}
			fmt.Fprintf(sb, "\nExecution context:\n%s\n", execContext)
		}
		if st.Status == database.SubtaskStatusWaiting {
			fmt.Fprintf(sb, "\nNote: subtask is waiting for user input (ask state).\n")
			fmt.Fprintf(sb, "Use %s to provide the answer and resume execution.\n", SubmitFlowInputToolName)
		}

		msgLimit := msgLogLimitNormal
		if verbose {
			msgLimit = msgLogLimitVerbose
		}
		msgLogs, err := t.appendSubtaskMsgLogs(ctx, st.ID, msgLimit)
		if err != nil {
			return "", fmt.Errorf("failed to get subtask msg logs: %w", err)
		}
		sb.WriteString(msgLogs)

View on GitHub (pinned to ea665308ba)

Solutions

1. Inspect the wrapped cause to classify the summarizer failure (auth/quota/network/cancel).
2. Re-validate provider credentials and endpoint, then retry the verbose status call.
3. Retry transient failures after a short backoff (rate limits especially).
4. Call flow_status with verbose=false to skip the context summarization path entirely.
5. Trim stored subtask contexts below 2*descriptionLimit so no LLM call is needed.

Example fix

// before: verbose only, no fallback
execContext, err := t.getDescriptionText(ctx, st.Context)
if err != nil {
	return "", fmt.Errorf("failed to get subtask context: %w", err)
}

// after: fall back to truncated raw context on summarizer failure
execContext, err := t.getDescriptionText(ctx, st.Context)
if err != nil {
	log.Warn("context summarization failed; using raw truncation", "err", err)
	execContext = truncateText(st.Context, descriptionLimit)
}

// avoid the summarizer entirely in the common case
if verbose && st.Context != "" && len(st.Context) <= 2*descriptionLimit {
	execContext := truncateText(st.Context, descriptionLimit) // no LLM call
}

func contextNeedsLLM(st database.Subtask, verbose bool, hasSummarizer bool) bool {
	return verbose && st.Context != "" && hasSummarizer && len(st.Context) > 2*descriptionLimit
}

execContext, err := getDescriptionText(ctx, st.Context)
if err != nil {
	// degrade: show raw truncated context rather than failing verbose status
	log.Warn("subtask context summarization failed", "err", err)
	execContext = truncateText(st.Context, descriptionLimit)
}

When it happens

Trigger: flow_status tool called with verbose=true while the running/waiting subtask has st.Context set and longer than 2*descriptionLimit characters, and the summarizer fails: provider auth error, rate limit/quota, network outage, or context cancellation during the LLM call.

Common situations: Verbose status polling (debugging sessions) coinciding with a provider outage or expired key; large execution contexts produced by long agent chains; upstream HTTP timeout cancelling summarization of a large context blob.

Related errors

• failed to get active task result: %w
• failed to set flow %d status: %w
• failed to renew flow %d status: %w
• failed to get flow %d status: %w
• flow %d is in unknown status: %s

AI-assisted analysis of vxcontrol/pentagi@ea665308ba (2026-09-01). Data as JSON: /api/errors/1bb647b1abc9221e. Report an issue: GitHub.