modWithoutSuffix := mod
	noun := "module"
	if before, found := strings.CutSuffix(mod.Version, "/go.mod"); found {
		noun = "go.mod"
		modWithoutSuffix.Version = before
	}

	db, lines, err := lookupSumDB(mod)
	if err != nil {
		return module.VersionError(modWithoutSuffix, fmt.Errorf("verifying %s: %v", noun, err))
	}

	have := mod.Path + " " + mod.Version + " " + h
	prefix := mod.Path + " " + mod.Version + " h1:"