1‌、运行下面的命令即可

export http_proxy=http://127.0.0.1:6666
export https_proxy=http://127.0.0.1:6666
sudo -E add-apt-repository ppa:linaro-maintainers/toolchain

‌2、查询是否设置成功

env |grep -i proxy

curl lumtest.com/myip.json

‌3、取消代理

unset http_proxy

unset https_proxy