performing download step (git clone) for 'hypercine'

[zhangkmsjtu]

platform:
ubuntu16.04
Building DICe: https://dicengine.github.io/dice/#BuildingDICe
no proxy

issues:
zhangkm@zhangkm-OptiPlex-3020:~/dice-2.0/build$ sudo make all install
Scanning dependencies of target hypercine
[ 1%] Creating directories for 'hypercine'
[ 1%] Performing download step (git clone) for 'hypercine'
正克隆到 'hypercine'...
fatal: unable to connect to github.com:
github.com[0: 20.205.243.166]: errno=连接超时

正克隆到 'hypercine'...
fatal: unable to connect to github.com:
github.com[0: 20.205.243.166]: errno=连接超时

正克隆到 'hypercine'...
fatal: unable to connect to github.com:
github.com[0: 20.205.243.166]: errno=连接超时

-- Had to git clone more than once:
3 times.
CMake Error at /home/zhangkm/dice-2.0/build/hypercine/tmp/hypercine-gitclone.cmake:40 (message):
Failed to clone repository: 'git://github.com/dicengine/hypercine.git'

CMakeFiles/hypercine.dir/build.make:89: recipe for target 'hypercine/src/hypercine-stamp/hypercine-download' failed
make[2]: *** [hypercine/src/hypercine-stamp/hypercine-download] Error 1
CMakeFiles/Makefile2:67: recipe for target 'CMakeFiles/hypercine.dir/all' failed
make[1]: *** [CMakeFiles/hypercine.dir/all] Error 2
Makefile:127: recipe for target 'all' failed
make: *** [all] Error 2
zhangkm@zhangkm-OptiPlex-3020:~/dice-2.0/build$

Having trouble running： make all
but, running :git clone git@github.com:dicengine/hypercine.git ./hypercine it is OK.
see below: