vxcontrol/pentagi · error

failed to read current content of %s before editing: %w

Error message

failed to read current content of %s before editing: %w

What it means

EditFile reads the current file from the container (readFileFromContainer, which also uses tar streaming via CopyFromContainer) before applying the diff. This error wraps that read failing — so the real cause is one of the read-side failures: file not found, container not running, tar extraction error, or Docker API/daemon problems. No modification is made.

Source

Thrown at backend/pkg/tools/terminal.go:512

	return nil
}

// EditFile applies a unified diff to the file at path: it reads the current
// content, applies the diff to it entirely in memory (see applyUnifiedDiff),
// and only if every hunk applied cleanly writes the result back - a diff
// that doesn't fully apply leaves the file untouched.
func (t *terminal) EditFile(ctx context.Context, flowID int64, path, diffText string) (string, error) {
	if path == "" {
		return "", fmt.Errorf("path is required and cannot be empty")
	}
	if strings.TrimSpace(diffText) == "" {
		return "", fmt.Errorf("diff is required and cannot be empty")
	}

	current, err := t.readFileFromContainer(ctx, flowID, path)
	if err != nil {
		return "", fmt.Errorf("failed to read current content of %s before editing: %w", path, err)
	}

	newContent, hunksApplied, err := ApplyUnifiedDiff(current, diffText)
	if err != nil {
		return "", fmt.Errorf("failed to apply diff to %s: %w", path, err)
	}

	if err := t.writeFileToContainer(ctx, flowID, path, newContent); err != nil {
		return "", fmt.Errorf("failed to write edited content of %s: %w", path, err)
	}

	successMsg := fmt.Sprintf("Applied %d diff hunk(s) to %s (%d -> %d bytes)", hunksApplied, path, len(current), len(newContent))
	styledMsg := fmt.Sprintf("%s%s%s%s", ansiColorSystemMsg, successMsg, ansiColorReset, ansiLineTerminator)
	if _, err := t.tlp.PutMsg(ctx, database.TermlogTypeStdin, styledMsg, t.containerID, t.taskID, t.subtaskID); err != nil {
		return "", fmt.Errorf("failed to put terminal log (edit file cmd): %w", err)
	}

	return successMsg, nil

View on GitHub (pinned to ea665308ba)

Solutions

1. Verify the file exists in the container (e.g. run `ls -l <path>` via the terminal tool) and correct the path
2. Read the file first with the ReadFile tool to confirm accessibility before EditFile
3. Check the flow container is running and restart it if it exited
4. Read the wrapped %w cause: 'no such file' → fix path; 'container not running' → restart flow; daemon errors → check Docker connectivity
5. If the file should exist, create it with WriteFile before editing

Example fix

// caller-side pre-check
// before
msg, err := term.EditFile(ctx, flowID, path, diff)
// after
if _, err := term.ReadFile(ctx, flowID, "", path); err != nil {
    return fmt.Errorf("cannot edit %s: file not readable (%v); create it first or fix the path", path, err)
}
msg, err := term.EditFile(ctx, flowID, path, diff)

// Confirm the file exists and is readable before editing
out, err := term.ExecuteCommand(ctx, flowID, fmt.Sprintf("test -f %s && echo OK", path))
if err != nil || !strings.Contains(out, "OK") {
    return fmt.Errorf("%s does not exist in container; create it with write_file first", path)
}

msg, err := term.EditFile(ctx, flowID, path, diff)
if err != nil && strings.Contains(err.Error(), "failed to read current content") {
    if strings.Contains(err.Error(), "no such file") {
        // create the file with WriteFile, then retry the edit
    }
}

When it happens

Trigger: Editing a path that does not exist in the container; the flow container stopped or was removed; CopyFromContainer failed because the target is a directory or a special file; Docker daemon connection error mid-flow.

Common situations: Agent hallucinating a file path that was never created; editing a file after container restart with a fresh filesystem (non-persistent layer); typo in path casing; editing a directory instead of a file.

Related errors

• runtime verification failed: %w
• container runtime is not operational
• failed to create exec process: %w
• failed to write edited content of %s: %w
• failed to attach file-check exec: %w

AI-assisted analysis of vxcontrol/pentagi@ea665308ba (2026-09-01). Data as JSON: /api/errors/aeb590ab80e4f872. Report an issue: GitHub.