nix.conf: builders-use-substitutes

Fixes #937

1 files changed, 14 insertions, 0 deletions

diff --git a/doc/manual/command-ref/conf-file.xml b/doc/manual/command-ref/conf-file.xml
index 87f05fb1c704..2ddca991f19c 100644
--- a/doc/manual/command-ref/conf-file.xml
+++ b/doc/manual/command-ref/conf-file.xml
@@ -321,6 +321,20 @@ false</literal>.</para>
   </varlistentry>
 
 
+  <varlistentry><term><literal>builders-use-substitutes</literal></term>
+
+    <listitem><para>If set to <literal>true</literal>, Nix will instruct
+    remote build machines to use their own binary substitutes if available. In
+    practical terms, this means that remote hosts will fetch as many build
+    dependencies as possible from their own substitutes (e.g, from
+    <literal>cache.nixos.org</literal>), instead of waiting for this host to
+    upload them all. This can drastically reduce build times if the network
+    connection between this computer and the remote build host is slow. Defaults
+    to <literal>false</literal>.</para></listitem>
+
+  </varlistentry>
+
+
   <varlistentry><term><literal>fallback</literal></term>
 
     <listitem><para>If set to <literal>true</literal>, Nix will fall