Unable to clone libi0

[lingu]

I have difficulty cloning libi0 as shown below.

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Sun Aug 30 17:29:07 CST 2015 lingu@worker3e5:/home/lingu/forest> cod clone libi0
The Ground is the directory where all the code trees reside.
The code tree will be cloned in the current Ground: /home/lingu/forest
Cloning into 'libi0'...
error: Failed connect to github.com:443; Connection timed out while accessing https://github.com/layerzero/libi0/info/refs
fatal: HTTP request failed
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