pyrox.dev
1<section xmlns="http://docbook.org/ns/docbook"
2 xmlns:xlink="http://www.w3.org/1999/xlink"
3 xmlns:xi="http://www.w3.org/2001/XInclude"
4 version="5.0"
5 xml:id="sec-nix-network-issues">
6 <title>Network Problems</title>
7
8 <para>
9 Nix uses a so-called <emphasis>binary cache</emphasis> to optimise building a
10 package from source into downloading it as a pre-built binary. That is,
11 whenever a command like <command>nixos-rebuild</command> needs a path in the
12 Nix store, Nix will try to download that path from the Internet rather than
13 build it from source. The default binary cache is
14 <uri>https://cache.nixos.org/</uri>. If this cache is unreachable, Nix
15 operations may take a long time due to HTTP connection timeouts. You can
16 disable the use of the binary cache by adding <option>--option
17 use-binary-caches false</option>, e.g.
18<screen>
19# nixos-rebuild switch --option use-binary-caches false
20</screen>
21 If you have an alternative binary cache at your disposal, you can use it
22 instead:
23<screen>
24# nixos-rebuild switch --option binary-caches http://my-cache.example.org/
25</screen>
26 </para>
27</section>