Log when 'cloudtail_utils.py stop' can't find cloudtail PID.

scripts/slave/recipe_modules/goma/resources/cloudtail_utils.py

Index: scripts/slave/recipe_modules/goma/resources/cloudtail_utils.py
diff --git a/scripts/slave/recipe_modules/goma/resources/cloudtail_utils.py b/scripts/slave/recipe_modules/goma/resources/cloudtail_utils.py
index af8e3e1d11757601ad6a5f8501c979cebddf8142..bfe97d81c9b55bf1b895a97ad565957f9d21e63d 100644
--- a/scripts/slave/recipe_modules/goma/resources/cloudtail_utils.py
+++ b/scripts/slave/recipe_modules/goma/resources/cloudtail_utils.py
@@ -65,11 +65,14 @@ def wait_termination(pid):
     NotDiedError: if cloudtail is running after 10 seconds waiting,
                   NotDiedError is raised.
   """
+
   try:
     os.kill(pid, signal.SIGINT)
   except OSError as e:
     # Already dead?
     if e.errno in (errno.ECHILD, errno.EPERM, errno.ESRCH):
+      print('Can\'t send SIGINT to process %d. Already dead? Errno %d.' %
+            (pid, e.errno))
       return
     raise