From 303d5fa2c437cfb3a6922197619bf8cbbc998b66 Mon Sep 17 00:00:00 2001
From: Daiderd Jordan <daiderd@gmail.com>
Date: Thu, 22 Dec 2016 23:25:32 +0100
Subject: [PATCH] enable --dry-run for darwin-rebuild

---
 pkgs/nix-tools/darwin-rebuild.sh | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/pkgs/nix-tools/darwin-rebuild.sh b/pkgs/nix-tools/darwin-rebuild.sh
index db8029ed..ca8e6b1b 100644
--- a/pkgs/nix-tools/darwin-rebuild.sh
+++ b/pkgs/nix-tools/darwin-rebuild.sh
@@ -28,7 +28,7 @@ while [ "$#" -gt 0 ]; do
     switch|build)
       action="$i"
       ;;
-    --show-trace|--no-build-hook|--keep-failed|-K|--verbose|-v|-vv|-vvv|-vvvv|-vvvvv|--fallback|-Q)
+    --show-trace|--no-build-hook|--dry-run|--keep-failed|-K|--verbose|-v|-vv|-vvv|-vvvv|-vvvvv|--fallback|-Q)
       extraBuildFlags+=("$i")
       ;;
     --max-jobs|-j|--cores|-I)
@@ -73,6 +73,8 @@ if [ "$action" = switch -o "$action" = build ]; then
   systemConfig="$(nix-build '<darwin>' ${extraBuildFlags[@]} --no-out-link -A system)"
 fi
 
+if [ -z "$systemConfig" ]; then exit 0; fi
+
 if [ "$action" = build ]; then
   echo $systemConfig
 fi