diff --git a/tools/VERSION b/tools/VERSION
index 0d220d1..0e38057 100644
--- a/tools/VERSION
+++ b/tools/VERSION
@@ -28,4 +28,4 @@
 MINOR 12
 PATCH 0
 PRERELEASE 2
-PRERELEASE_PATCH 0
+PRERELEASE_PATCH 1
diff --git a/tools/clean_output_directory.py b/tools/clean_output_directory.py
index e41671c..79df929 100755
--- a/tools/clean_output_directory.py
+++ b/tools/clean_output_directory.py
@@ -7,6 +7,7 @@
 
 import shutil
 import sys
+import subprocess
 import utils
 
 def Main():