Rust Nickel Hello World 教程在运行时抛出依赖错误

Question

我正在学习 Rust，并在 http://reddit.com/r/rust 上看到了一篇帖子昨天Nickel .作为一名 Node.js 开发人员，我有兴趣在空闲时间检查一下。

我从 http://rust-lang.org 下载了 Rust 1.0.0-beta DMG .

我关注了 Hello World准确教程，当我在我的终端中执行 cargo run 时，我收到以下错误:

Robs-MacBook-Pro:nickel-demo rob$ cargo run
   Compiling nickel-demo v0.0.1 (file:///Users/rob/Workbench/nickel-demo)
src/main.rs:4:1: 4:21 error: an external crate named `nickel` has already been imported into this module [E0259]
src/main.rs:4 extern crate nickel;
              ^~~~~~~~~~~~~~~~~~~~
error: aborting due to previous error
Could not compile `nickel-demo`.

Nickel 演示的 Hello World main.rs 文件如下所示:

extern crate nickel;

#[macro_use] extern crate nickel_macros;
extern crate nickel;

use nickel::Nickel;

fn main() {
    let mut server = Nickel::new();

    server.utilize(router! {
        get "**" => |_req, _res| {
            "Hello world!"
        }
    });

    server.listen("127.0.0.1:6767");
}

当我在编辑器中输入这段代码时，我特别觉得我在文件中声明了两次 extern crate nickel; 很奇怪。收到错误后，我将代码重构为:

extern crate nickel;

#[macro_use] extern crate nickel_macros;

use nickel::Nickel;

...

我得到这个错误:

Robs-MacBook-Pro:nickel-demo rob$ cargo run
   Compiling nickel-demo v0.0.1 (file:///Users/rob/Workbench/nickel-demo)
     Running `target/debug/nickel-demo`
Listening on http://127.0.0.1:6767
Ctrl-C to shutdown server
thread '<main>' panicked at 'arithmetic operation overflowed', /Users/rob/.cargo/registry/src/github.com-1ecc6299db9ec823/hyper-0.3.11/src/server/mod.rs:90
An unknown error occurred

Answer 1

算术运算溢出 错误似乎是上游问题。它还会影响镍所依赖的 hyper。

参见 https://github.com/seanmonstar/num_cpus/issues/2

作为临时解决方法，使用 cargo build --release 来完全阻止检查。