The ns-allinone-3.20 package is taken for installation.Following error occurs 


Build failed
 -> task in 'bench-simulator' failed (exit status 1): 
        {task 174209260: cxx bench-simulator.cc -> bench-simulator.cc.2.o}
['g++34', '-O0', '-ggdb', '-g3', '-Wall', '-Werror', '-fstrict-aliasing', '-Wstrict-aliasing', '-pthread', '-I.', '-I..', '-DNS3_ASSERT_ENABLE', '-DNS3_LOG_ENABLE', '-DHAVE_SYS_IOCTL_H=1', '-DHAVE_IF_NETS_H=1', '-DHAVE_NET_ETHERNET_H=1', '-DHAVE_PACKET_H=1', '-DHAVE_IF_TUN_H=1', '../utils/bench-simulator.cc', '-c', '-o', 'utils/bench-simulator.cc.2.o']
 -> task in 'print-introspected-doxygen' failed (exit status 1): 
        {task 174219404: cxx print-introspected-doxygen.cc -> print-introspected-doxygen.cc.4.o}
['g++34', '-O0', '-ggdb', '-g3', '-Wall', '-Werror', '-fstrict-aliasing', '-Wstrict-aliasing', '-pthread', '-I.', '-I..', '-I/usr/include/libxml2', '-DNS3_ASSERT_ENABLE', '-DNS3_LOG_ENABLE', '-DHAVE_SYS_IOCTL_H=1', '-DHAVE_IF_NETS_H=1', '-DHAVE_NET_ETHERNET_H=1', '-DHAVE_PACKET_H=1', '-DHAVE_IF_TUN_H=1', '../utils/print-introspected-doxygen.cc', '-c', '-o', 'utils/print-introspected-doxygen.cc.4.o']
Traceback (most recent call last):
  File "./build.py", line 170, in <module>
    sys.exit(main(sys.argv))
  File "./build.py", line 161, in main
    build_ns3(config, build_examples, build_tests, args, build_options)
  File "./build.py", line 81, in build_ns3
    run_command([sys.executable, "waf", "build"] + build_options)
  File "/home/ambresh/Desktop/NS3/ns-allinone-3.20/util.py", line 24, in run_command
    raise CommandError("Command %r exited with code %i" % (argv, retval))
util.CommandError: Command ['/usr/local/bin/python', 'waf', 'build'] exited with code 1