new_build_env: use python3

new_build_env.py

-#!/usr/bin/python
+#!/usr/bin/python3
 
 import os
 import sys
@@ -30,7 +30,7 @@ def main():
     parser.add_option('-c', '--clean', dest='CLEAN', action="store_true",
                       default = False,
                       help="Remove all files from current directory before")
-    parser.add_option('-v', '--verbose', dest='verbose', action='count',
+    parser.add_option('-v', '--verbose', dest='verbose', action='count', default=0,
                       help="Increase verbosity (specify multiple times for more)")
     parser.add_option('', '--fail-trace-all', dest='FAIL_TRACE_ALL', default = "no",
                       help="Trace all testcases")