lima-vm/lima · error

failed to convert %q to raw: %w

Error message

failed to convert %q to raw: %w

What it means

ensureRawInCache converts a cached image to raw sparse format via proxyimgutil's DiskUtil.Convert; any failure from the converter is wrapped as this error, naming the source image path. It is the core "conversion step failed" error of the raw-image cache pipeline.

Source

Thrown at pkg/downloader/downloader.go:476

	}
	return res, nil
}

// ensureRawInCache converts any image to raw and places it in the cache(imgconv/raw). It also creates a
// digest file for the raw image(imgconv/raw.digest). Returns the converted image path, the raw digest, and any error.
func ensureRawInCache(ctx context.Context, imagePath, format string, originalDigest digest.Digest) (string, digest.Digest, error) {
	imgConvPath := filepath.Join(filepath.Dir(imagePath), "imgconv")
	if err := os.MkdirAll(imgConvPath, 0o700); err != nil {
		return "", "", err
	}
	rawImgConvPath := filepath.Join(imgConvPath, "raw")

	logrus.Infof("Converting %s image to raw sparse format in cache: %q", format, rawImgConvPath)
	rawPathTmp := filepath.Join(imgConvPath, "raw.tmp")
	defer os.Remove(rawPathTmp)
	diskUtil := proxyimgutil.NewDiskUtil(ctx)
	if err := diskUtil.Convert(ctx, raw.Type, imagePath, rawPathTmp, nil, false); err != nil {
		return "", "", fmt.Errorf("failed to convert %q to raw: %w", imagePath, err)
	}

	// Ensure the image is sparse to save cache space.
	rawTmpF, err := os.OpenFile(rawPathTmp, os.O_RDWR, 0o644)
	if err != nil {
		return "", "", fmt.Errorf("failed to open raw tmp file %q: %w", rawPathTmp, err)
	}
	fi, err := rawTmpF.Stat()
	if err != nil {
		_ = rawTmpF.Close()
		return "", "", fmt.Errorf("failed to stat raw tmp file %q: %w", rawPathTmp, err)
	}
	if err := diskUtil.MakeSparse(ctx, rawTmpF, fi.Size()); err != nil {
		logrus.WithError(err).Warnf("Failed to make %q sparse (non-fatal)", rawPathTmp)
	}
	if err := rawTmpF.Close(); err != nil {
		return "", "", fmt.Errorf("failed to close raw tmp file %q: %w", rawPathTmp, err)
	}

View on GitHub (pinned to dd909d0973)

Solutions

1. Inspect the wrapped %w error for the converter's own message (e.g. 'no space left on device').
2. Free space in the cache/imgConv directory and remove stale raw.tmp files.
3. Delete the corrupt cached source image and re-download.
4. Install or update the conversion tooling the converter depends on.

Example fix

// before: ENOSPC during conversion
$ df -h ~/.cache/lima && du -sh ~/.cache/lima/*
$ rm -f ~/.cache/lima/images/*/raw.tmp
// after: retry download; conversion completes

if free, err := disk.Free(cacheDir); err == nil && free < minRequiredBytes {
    return errors.New("cache volume too low on space for raw conversion")
}

res, err := d.Download(ctx, local, url)
var convErr *fmt.WrapError // inspect via errors.Unwrap chain
if err != nil && strings.Contains(err.Error(), "failed to convert") {
    if wrapped := errors.Unwrap(errors.Unwrap(err)); wrapped != nil {
        log.Errorf("conversion root cause: %v", wrapped)
    }
}

When it happens

Trigger: DiskUtil.Convert fails inside ensureRawInCache (called from getCached or fetch) — source image unreadable, conversion backend unavailable, output volume full (raw.tmp write), or the image format cannot be converted by the selected raw.Type converter.

Common situations: Cache dir on a full or read-only volume; exotic/encrypted disk images the converter rejects; partial/corrupt source image in cache from an earlier failed download.

Related errors

• failed to convert image to raw: %w
• caching-only mode requires the cache directory to be specifi
• invalid digest in raw digest file %q: %w
• failed to read raw digest file %q: %w
• failed to open raw tmp file %q: %w

AI-assisted analysis of lima-vm/lima@dd909d0973 (2026-09-01). Data as JSON: /api/errors/3d49fe0232b75587. Report an issue: GitHub.