From 083134617589fcdbad89a554bb8d6681f6072c00 Mon Sep 17 00:00:00 2001
From: DHuan <huandzh@gmail.com>
Date: Mon, 22 May 2023 18:07:59 +0800
Subject: [PATCH] help: nix-channels: prevent auto appending

Add code to demonstrate how to prevent the automatic appending of the default cache site, which can be especial helpful for users who are completely unable to reach the site:

See also: https://github.com/NixOS/nixpkgs/issues/158356#issuecomment-1556882689
---
 help/_posts/2023-03-10-nix-channels.md | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/help/_posts/2023-03-10-nix-channels.md b/help/_posts/2023-03-10-nix-channels.md
index 610a4b4..1b23da8 100644
--- a/help/_posts/2023-03-10-nix-channels.md
+++ b/help/_posts/2023-03-10-nix-channels.md
@@ -90,6 +90,21 @@ mirrorid: nix-channels
 </code>
 </pre>
 
+如果因为无法访问 https://cache.nixos.org 等原因，希望避免自动添加该默认地址，请在配置中使用`lib.mkForce`。
+
+{% raw %}
+<script id="template-2-1" type="x-tmpl-markup">
+	  # load `lib` into namespace at the file head with `{ config, pkgs, lib, ... }:`
+    nix.settings.substituters = lib.mkForce [ "{{http_protocol}}{{mirror}}/store" ];
+    </script>
+{% endraw %}
+
+<p></p>
+
+<pre>
+<code id="content-2-1" class="language-nix" data-template="#template-2-1" data-select="#http-select,#sudo-select">
+</code>
+</pre>
 
 #### 临时使用