在Rust中，cargo使用国内镜像源

一个编程语言依赖包管理的普通问题。

cargo解决得比较优雅。

一，新建$HOME/.cargo/config文件

[source.crates-io]
registry = "https://github.com/rust-lang/crates.io-index"
replace-with = 'ustc'
[source.ustc]
registry = "git://mirrors.ustc.edu.cn/crates.io-index"

二，项目cargo.toml内容

[package]
name = "guessing_game"
version = "0.1.0"
authors = ["aguncn <aguncn@163.com>"]
edition = "2018"

# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html

[dependencies]
rand = "0.5.5"

三，cargo build命令

四，更新完成之后,Cargo.lock文件内容

# This file is automatically @generated by Cargo.
# It is not intended for manual editing.
[[package]]
name = "bitflags"
version = "1.2.1"
source = "registry+https://github.com/rust-lang/crates.io-index"

[[package]]
name = "cloudabi"
version = "0.0.3"
source = "registry+https://github.com/rust-lang/crates.io-index"
dependencies = [
 "bitflags 1.2.1 (registry+https://github.com/rust-lang/crates.io-index)",
]

[[package]]
name = "fuchsia-cprng"
version = "0.1.1"
source = "registry+https://github.com/rust-lang/crates.io-index"

[[package]]
name = "guessing_game"
version = "0.1.0"
dependencies = [
 "rand 0.5.6 (registry+https://github.com/rust-lang/crates.io-index)",
]

[[package]]
name = "libc"
version = "0.2.65"
source = "registry+https://github.com/rust-lang/crates.io-index"

[[package]]
name = "rand"
version = "0.5.6"
source = "registry+https://github.com/rust-lang/crates.io-index"
dependencies = [
 "cloudabi 0.0.3 (registry+https://github.com/rust-lang/crates.io-index)",
 "fuchsia-cprng 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)",
 "libc 0.2.65 (registry+https://github.com/rust-lang/crates.io-index)",
 "rand_core 0.3.1 (registry+https://github.com/rust-lang/crates.io-index)",
 "winapi 0.3.8 (registry+https://github.com/rust-lang/crates.io-index)",
]

[[package]]
name = "rand_core"
version = "0.3.1"
source = "registry+https://github.com/rust-lang/crates.io-index"
dependencies = [
 "rand_core 0.4.2 (registry+https://github.com/rust-lang/crates.io-index)",
]

[[package]]
name = "rand_core"
version = "0.4.2"
source = "registry+https://github.com/rust-lang/crates.io-index"

[[package]]
name = "winapi"
version = "0.3.8"
source = "registry+https://github.com/rust-lang/crates.io-index"
dependencies = [
 "winapi-i686-pc-windows-gnu 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)",
 "winapi-x86_64-pc-windows-gnu 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)",
]

[[package]]
name = "winapi-i686-pc-windows-gnu"
version = "0.4.0"
source = "registry+https://github.com/rust-lang/crates.io-index"

[[package]]
name = "winapi-x86_64-pc-windows-gnu"
version = "0.4.0"
source = "registry+https://github.com/rust-lang/crates.io-index"

[metadata]
"checksum bitflags 1.2.1 (registry+https://github.com/rust-lang/crates.io-index)" = "cf1de2fe8c75bc145a2f577add951f8134889b4795d47466a54a5c846d691693"
"checksum cloudabi 0.0.3 (registry+https://github.com/rust-lang/crates.io-index)" = "ddfc5b9aa5d4507acaf872de71051dfd0e309860e88966e1051e462a077aac4f"
"checksum fuchsia-cprng 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)" = "a06f77d526c1a601b7c4cdd98f54b5eaabffc14d5f2f0296febdc7f357c6d3ba"
"checksum libc 0.2.65 (registry+https://github.com/rust-lang/crates.io-index)" = "1a31a0627fdf1f6a39ec0dd577e101440b7db22672c0901fe00a9a6fbb5c24e8"
"checksum rand 0.5.6 (registry+https://github.com/rust-lang/crates.io-index)" = "c618c47cd3ebd209790115ab837de41425723956ad3ce2e6a7f09890947cacb9"
"checksum rand_core 0.3.1 (registry+https://github.com/rust-lang/crates.io-index)" = "7a6fdeb83b075e8266dcc8762c22776f6877a63111121f5f8c7411e5be7eed4b"
"checksum rand_core 0.4.2 (registry+https://github.com/rust-lang/crates.io-index)" = "9c33a3c44ca05fa6f1807d8e6743f3824e8509beca625669633be0acbdf509dc"
"checksum winapi 0.3.8 (registry+https://github.com/rust-lang/crates.io-index)" = "8093091eeb260906a183e6ae1abdba2ef5ef2257a21801128899c3fc699229c6"
"checksum winapi-i686-pc-windows-gnu 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)" = "ac3b87c63620426dd9b991e5ce0329eff545bccbbb34f3be09ff6fb6ab51b7b6"
"checksum winapi-x86_64-pc-windows-gnu 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)" = "712e227841d057c1ee1cd2fb22fa7e5a5461ae8e48fa2ca79ec42cfc1931183f"

五，完了