Fetch the repository succeeded.
编译失败，no method named `c` found for type `std::result::Result<i32, std::io::Error>` in the current scope
源代码中的[dependencies] error-chain链接地址失效了，我把error-chain替换成了error-chain = "0.12.1"
编译报了大量的错误
error[E0599]: no method named `c` found for type `std::result::Result<(), err::Error>` in the current
