很多时候，我出门在外，在那里我设置了二进制缓存192.168.0.6，并且遇到了如下错误：
sudo nix-channel --update
unpacking channels...
warning: unable to download 'http://192.168.0.6:8899/nix-cache-info': Couldn't connect to server (7); retrying in 305 ms
warning: unable to download 'http://192.168.0.6:8899/nix-cache-info': Couldn't connect to server (7); retrying in 693 ms
warning: unable to download 'http://192.168.0.6:8899/nix-cache-info': Couldn't connect to server (7); retrying in 1021 ms
warning: unable to download 'http://192.168.0.6:8899/nix-cache-info': Couldn't connect to server (7); retrying in 2429 ms
warning: unable to download 'http://192.168.0.6:8899/nix-cache-info': Couldn't connect to server (7)
^Cerror: interrupted by the user
我怎样才能删除/忽略它？
由于以下原因，我无法重建我的配置：
似乎有一个选项nixos-rebuild switch --fallback --show-trace --option binary-caches https://cache.nixos.org/ forced （在这里找到https://github.com/NixOS/nix/issues/1990#issuecomment-377969731）
unstable但是，当我在配置中引用一个通道时，它失败了：
building Nix...
building the system configuration...
error: file 'unstable' was not found in the Nix search path (add it using $NIX_PATH or -I), at /etc/nixos/chris.nix:25:21
(use '--show-trace' to show detailed location information)