From b9dd7509b62dbc7b5e401cc5441f2a0e81616eae Mon Sep 17 00:00:00 2001
From: Eelco Dolstra <eelco.dolstra@logicblox.com>
Date: Tue, 18 Sep 2007 15:38:05 +0000
Subject: [PATCH] * nixos-rebuild: before building NixOS, first build the
 latest Nix and   use that one to build NixOS.  This will make it easier to
 use   bleeding-edge features in the NixOS expressions.

svn path=/nixos/trunk/; revision=9336
---
 default.nix                |  2 ++
 installer/nixos-rebuild.sh | 10 ++++++++++
 2 files changed, 12 insertions(+)

diff --git a/default.nix b/default.nix
index 90aa4d33ad9..889d2ca873f 100644
--- a/default.nix
+++ b/default.nix
@@ -26,6 +26,8 @@ in
     config
     ;
 
+  nixFallback = system.nix;
+
   manifests = system.config.get ["installer" "manifests"]; # exported here because nixos-rebuild uses it
 
   upstartJobsCombined = system.upstartJobs;
diff --git a/installer/nixos-rebuild.sh b/installer/nixos-rebuild.sh
index 94ef51ee468..fbbd3e691f7 100644
--- a/installer/nixos-rebuild.sh
+++ b/installer/nixos-rebuild.sh
@@ -40,6 +40,13 @@ if test -z "$NIXOS_NO_PULL"; then
 fi
 
 
+# First build Nix, since NixOS may require a newer version than the
+# current one.  Of course, the same goes for Nixpkgs, but Nixpkgs is
+# more conservative.
+nix-build $NIXOS -A nixFallback -o $HOME/nix-tmp
+PATH=$HOME/nix-tmp/bin:$PATH
+
+
 # Either upgrade the configuration in the system profile (for "switch"
 # or "boot"), or just build it and create a symlink "result" in the
 # current directory (for "build" and "test").
@@ -69,3 +76,6 @@ active system configuration may be garbage collected!  This may render
 the system inoperable (though a reboot will fix things).
 EOF
 fi
+
+
+rm -f $HOME/nix-tmp