From 5b7c019e2a5b320589d9d7401ac072e5a0a1dffd Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Llu=C3=ADs=20Batlle=20i=20Rossell?= <viric@viric.name>
Date: Wed, 27 Jun 2012 21:36:46 +0200
Subject: [PATCH] nixos-rebuild: make 'pull' fail in case it did not pull
 anything.

---
 modules/installer/tools/nixos-rebuild.sh | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/modules/installer/tools/nixos-rebuild.sh b/modules/installer/tools/nixos-rebuild.sh
index 29927f8a126..98b46cb7cdb 100644
--- a/modules/installer/tools/nixos-rebuild.sh
+++ b/modules/installer/tools/nixos-rebuild.sh
@@ -125,9 +125,13 @@ fi
 # Pull the manifests defined in the configuration (the "manifests"
 # attribute).  Wonderfully hacky.
 if [ -n "$pullManifest" -o "$action" = pull ]; then
+    set -o pipefail
     manifests=$(nix-instantiate --eval-only --xml --strict '<nixos>' -A manifests \
         | grep '<string'  | sed 's^.*"\(.*\)".*^\1^g')
 
+    set -o nopipefail
+    [ "$action" = pull -a $? -ne 0 ] && exit 1
+
     mkdir -p /nix/var/nix/channel-cache
     for i in $manifests; do
         NIX_DOWNLOAD_CACHE=/nix/var/nix/channel-cache nix-pull $i || true