def enforceBool(prompt):
    """
    Enforces a boolean/YesNo value at a prompt
    Args:
        prompt: String for user input prompt
    Returns:
        Error string if invalid
        Test input if valid
    """
    testInput = input(prompt)
    if testInput in ['true', 'True', 'TRUE', 'Yes', 'yes', 'YES']:
        return True
    elif testInput in ['false', 'False', 'FALSE', 'No', 'no', 'NO']:
        return False
    else:
        return f'Input "{testInput}" cannot be converted to a boolean'