Function fetchHash

internal/update/update.go:257–288

fetchHash downloads codehamr_checksums.txt and returns the hash for asset. The manifest is one line per asset, " "; we match the last field so a future prefix tweak still works. A scanner read error is surfaced, not dropped as "", nil: Apply treats "no entry" as a fatal misma

(ctx context.Context, asset string)

// orphanSweepAge is how old a .codehamr-update-* temp must be before the
// launch sweep treats it as orphaned rather than another instance's live
// download; comfortably past any Apply budget.
const orphanSweepAge = time.Hour

// fetchHash downloads codehamr_checksums.txt and returns the hash for asset.
// The manifest is one line per asset, "<hex-sha256>  <filename>"; we match the
// last field so a future prefix tweak still works.
//
// A scanner read error is surfaced, not dropped as "", nil: Apply treats "no
// entry" as a fatal mismatch, so silently turning a network glitch into "asset
// doesn't exist" would be a confusing error.
func fetchHash(ctx context.Context, asset string) (string, error) {
	req, err := http.NewRequestWithContext(ctx, "GET", checksumsURL, nil)
	if err != nil {
		return "", err
	}
	resp, err := (&http.Client{Timeout: fetchTimeout}).Do(req)
	if err != nil {
		return "", err
	}
	defer resp.Body.Close()
	if resp.StatusCode != http.StatusOK {
		return "", fmt.Errorf("non-200: %d", resp.StatusCode)
	}
	sc := bufio.NewScanner(resp.Body)
	for sc.Scan() {
		line := strings.TrimSpace(sc.Text())
		if line == "" {
			continue
		}
		fields := strings.Fields(line)
		if len(fields) < 2 {
			continue
		}
		if fields[len(fields)-1] == asset {