module.error
如果 module.status 为 'errored',则该属性包含模块在求值过程中抛出的异常。
如果状态是别的,访问这个属性会导致抛出异常。
值 undefined 不能用于由于可能与 throw undefined; 有歧义而没有抛出异常的情况。
对应于 ECMAScript 规范中循环模块记录的 [[EvaluationError]] 字段。
If the module.status is 'errored', this property contains the exception
thrown by the module during evaluation. If the status is anything else,
accessing this property will result in a thrown exception.
The value undefined cannot be used for cases where there is not a thrown
exception due to possible ambiguity with throw undefined;.
Corresponds to the [[EvaluationError]] field of Cyclic Module Records
in the ECMAScript specification.