[cctest] adding --help option to output basic information about cctest

tools/testrunner/local/commands.py

Index: tools/testrunner/local/commands.py
diff --git a/tools/testrunner/local/commands.py b/tools/testrunner/local/commands.py
index 6aac3ffad588e561bfc5c6f196664d490bfdd4c8..a4df32c52aa4e72d1ca9eb89a381ef720106eba2 100644
--- a/tools/testrunner/local/commands.py
+++ b/tools/testrunner/local/commands.py
@@ -61,12 +61,18 @@ def RunProcess(verbose, timeout, args, **rest):
     error_mode = SEM_NOGPFAULTERRORBOX
     prev_error_mode = Win32SetErrorMode(error_mode)
     Win32SetErrorMode(error_mode | prev_error_mode)
-  process = subprocess.Popen(
-    args=popen_args,
-    stdout=subprocess.PIPE,
-    stderr=subprocess.PIPE,
-    **rest
-  )
+
+  try:
+    process = subprocess.Popen(
+      args=popen_args,
+      stdout=subprocess.PIPE,
+      stderr=subprocess.PIPE,
+      **rest
+    )
+  except Exception as e:
+    sys.stderr.write("Error executing: %s\n" % popen_args)
+    raise e
+
   if (utils.IsWindows() and prev_error_mode != SEM_INVALID_VALUE):
     Win32SetErrorMode(prev_error_mode)