raceback (most recent call last):
  File "/home/hex/ns-allinone-3.31/ns-3.31/.waf3-2.0.18-ff4ae9f5cc05353d3dc3aeff8854ae69/waflib/Scripting.py", line 119, in waf_entry_point
    run_commands()
  File "/home/hex/ns-allinone-3.31/ns-3.31/.waf3-2.0.18-ff4ae9f5cc05353d3dc3aeff8854ae69/waflib/Scripting.py", line 182, in run_commands
    ctx=run_command(cmd_name)
  File "/home/hex/ns-allinone-3.31/ns-3.31/.waf3-2.0.18-ff4ae9f5cc05353d3dc3aeff8854ae69/waflib/Scripting.py", line 173, in run_command
    ctx.execute()
  File "/home/hex/ns-allinone-3.31/ns-3.31/.waf3-2.0.18-ff4ae9f5cc05353d3dc3aeff8854ae69/waflib/Configure.py", line 85, in execute
    super(ConfigurationContext,self).execute()
  File "/home/hex/ns-allinone-3.31/ns-3.31/.waf3-2.0.18-ff4ae9f5cc05353d3dc3aeff8854ae69/waflib/Context.py", line 85, in execute
    self.recurse([os.path.dirname(g_module.root_path)])
  File "/home/hex/ns-allinone-3.31/ns-3.31/.waf3-2.0.18-ff4ae9f5cc05353d3dc3aeff8854ae69/waflib/Context.py", line 126, in recurse
    user_function(self)
  File "/home/hex/ns-allinone-3.31/ns-3.31/wscript", line 504, in configure
    opt.recurse('contrib/cryptopp')
NameError: name 'opt' is not defined