网络链接问题，墙与不可抗力

[EssenSea]

nix-shell -p git
git clone https://github.com/Ruixi-rebirth/flakes.git /mnt/etc/nixos/Flakes
cd /mnt/etc/nixos/Flakes/
nix develop --extra-experimental-features nix-command --extra-experimental-features flakes

需要翻墙，但安装镜像里面无法下载开启v2raya等代理服务( modify /etc/nixos/configration.nix cannot rebuild iso...)
is there any way to slove this?

btw, it seems readme.md is out of time as others .nix files has been modified.
one of bilibili fans.