[Resolved @ August 9,2016]"Error: unable get packages from source" "Caused by: [7] Couldn't connect to server"

The cargo run/build not work for me recently.(Since late of July)
The error msg as "warning: spurious networ error (1 tries remaining): [6] couldn't connect to server"; "Error: an unknown error happen" "Error: unable get packages from source" "Caused by: [7] Couldn't connect to server"

My computer can access github / facebook /Rust home page even I am in China, so the networking should be normal.

I try upgrade to latest Rust version, but the issue still existing.
Can somebody give a hint/hand for it? Thanks.

Rust Version:
GNU
X64
Nightly 0.13(August 5)
Rustc 0.12(August 5)

The issue resolved after use the proxy:

setting up file config at folder ~/.cargo to resolve it.
https://lug.ustc.edu.cn/wiki/mirrors/help/crates

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