Remove $NIX_BUILD_HOOK and $NIX_CURRENT_LOAD

This is to simplify remote build configuration. These environment
variables predate nix.conf.

The build hook now has a sensible default (namely build-remote).

The current load is kept in the Nix state directory now.

1 files changed, 2 insertions, 13 deletions

diff --git a/doc/manual/advanced-topics/distributed-builds.xml b/doc/manual/advanced-topics/distributed-builds.xml
index d5bc1c592..1957e1105 100644
--- a/doc/manual/advanced-topics/distributed-builds.xml
+++ b/doc/manual/advanced-topics/distributed-builds.xml
@@ -22,10 +22,7 @@ will call whenever it wants to build a derivation.  The build hook
 will perform it in the usual way if possible, or it can accept it, in
 which case it is responsible for somehow getting the inputs of the
 build to another machine, doing the build there, and getting the
-results back.  The details of the build hook protocol are described in
-the documentation of the <link
-linkend="envar-build-hook"><envar>NIX_BUILD_HOOK</envar>
-variable</link>.</para>
+results back.</para>
 
 <example xml:id='ex-remote-systems'><title>Remote machine configuration:
 <filename>remote-systems.conf</filename></title>
@@ -103,14 +100,6 @@ requiredSystemFeatures = [ "kvm" ];
 
 </orderedlist>
 
-You should also set up the environment variable
-<envar>NIX_CURRENT_LOAD</envar> to point at a directory (e.g.,
-<filename>/var/run/nix/current-load</filename>) that
-<filename>build-remote</filename> uses to remember how many builds
-it is currently executing remotely.  It doesn't look at the actual
-load on the remote machine, so if you have multiple instances of Nix
-running, they should use the same <envar>NIX_CURRENT_LOAD</envar>
-file.  Maybe in the future <filename>build-remote</filename> will
-look at the actual remote load.</para>
+</para>
 
 </chapter>