d2lang/d2 · error

error copying %s: %v

Error message

error copying %s: %v

What it means

copyPptxTemplateTo copies every non-skipped file from the embedded pptx template zip into the output zip via w.Copy(f); if any single entry fails to copy, the operation aborts with this error naming the entry. It indicates the output pptx would be incomplete or corrupt.

Source

Thrown at lib/pptx/pptx.go:303

func copyPptxTemplateTo(w *zip.Writer) error {
	reader := bytes.NewReader(PPTX_TEMPLATE)
	zipReader, err := zip.NewReader(reader, reader.Size())
	if err != nil {
		fmt.Printf("error creating zip reader: %v", err)
	}

	skipFiles := map[string]bool{
		"_rels/.rels": true,
		"ppt/slideMasters/_rels/slideMaster1.xml.rels": true,
	}

	for _, f := range zipReader.File {
		if skipFiles[f.Name] {
			continue
		}
		if err := w.Copy(f); err != nil {
			return fmt.Errorf("error copying %s: %v", f.Name, err)
		}
	}
	return nil
}

//go:embed templates/slide.xml.rels
var RELS_SLIDE_XML string

type RelsSlideXmlLinkContent struct {
	RelationshipID string
	ExternalUrl    string
	SlideIndex     int
}

type RelsSlideXmlContent struct {
	FileName       string
	RelationshipID string
	Links          []RelsSlideXmlLinkContent

View on GitHub (pinned to 0d69dca6f5)

Solutions

1. Check disk space and write permissions for the output path in SaveTo
2. Close the pptx file in other programs and retry
3. Verify the wrapped error (%v) identifies the zip writer cause
4. Retry the save; transient I/O errors often resolve
5. If custom skipFiles/template edits were made, verify the template zip integrity

Example fix

// before
err := pres.SaveTo(f)
// after
err := pres.SaveTo(f)
if err != nil && strings.Contains(err.Error(), "error copying") {
    log.Printf("template copy failed: %v — check disk space / file locks", err)
}

if st, err := os.Stat(outPath); err == nil { f, _ := os.OpenFile(outPath, os.O_WRONLY, 0); if f != nil { f.Close() } } // writability check

func isCopyError(err error) bool { return strings.Contains(err.Error(), "error copying ") }

err := pres.SaveTo(out)
if err != nil {
    if isCopyError(err) {
        log.Printf("pptx write failed: %v — check disk space and file locks", err)
        return retrySave(out)
    }
    return err
}

When it happens

Trigger: w.Copy(f) fails for a template entry — typically an underlying zip writer error such as the destination writer being closed, an I/O failure, or a corrupted template zip entry.

Common situations: Disk full or permission denied when writing SaveTo's destination; destination file locked by another process (e.g. PowerPoint open); corrupted embedded template.

Related errors

• cannot read a directory
• error decoding PNG image: %v
• no color stops in gradient
• %s is not a supported format. Supported formats are: %s
• failed to fully compile (partial render written) %s: %w

AI-assisted analysis of d2lang/d2@0d69dca6f5 (2026-08-31). Data as JSON: /api/errors/8e7fee39ea367a28. Report an issue: GitHub.