From dc7522b7caa60d872fd864b5d162166fe69a9571 Mon Sep 17 00:00:00 2001
From: armink <armink.ztl@gmail.com>
Date: Wed, 27 Jun 2018 08:27:45 +0800
Subject: [PATCH] [tools] Fix SCons build error when `RTT_EXEC_PATH` not found.

---
 tools/building.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/building.py b/tools/building.py
index 8fa1f96331..fee9553bcf 100644
--- a/tools/building.py
+++ b/tools/building.py
@@ -249,7 +249,7 @@ def PrepareBuilding(env, root_directory, has_libcpu=False, remove_components = [
 
     # auto change the 'RTT_EXEC_PATH' when 'rtconfig.EXEC_PATH' get failed
     if not os.path.exists(rtconfig.EXEC_PATH):
-        if os.environ['RTT_EXEC_PATH']:
+        if 'RTT_EXEC_PATH' in os.environ:
             # del the 'RTT_EXEC_PATH' and using the 'EXEC_PATH' setting on rtconfig.py
             del os.environ['RTT_EXEC_PATH']
             reload(rtconfig)