fix ruby
diff --git a/tools/run_tests/run_tests.py b/tools/run_tests/run_tests.py
index 09af055..7b2bc53 100755
--- a/tools/run_tests/run_tests.py
+++ b/tools/run_tests/run_tests.py
@@ -385,7 +385,7 @@
   def pre_build_steps(self):
     return [['tools/run_tests/pre_build_ruby.sh']]
 
-  def make_targets(self, test_regex):
+  def make_targets(self):
     return []
 
   def make_options(self):