<div>Hi£¬ everyone,</div><div>I had trouble installing NFD. To install it£¬I compiled from source and followed the steps in <a href="http://named-data.net/doc/NFD/current/INSTALL.html">http://named-data.net/doc/NFD/current/INSTALL.html</a> </div><div>When coming to the ¡°Build¡± step£¬I entered ¡°./waf¡± but meet the following error.</div><div>I successfully installed the version 0.5.1 last year. Recent version is 0.6.1 but installed unsuccessfully. What¡®s more, if I git clone the version 0.5.1, same error information appeared.</div><div>My environment is a completely new Ubuntu virtual machine.</div><div><br></div><blockquote formatblock="1" style="margin: 0.8em 0px 0.8em 2em; padding: 0px 0px 0px 0.7em; border-left: 2px solid rgb(221, 221, 221);"><pre>tan@tan-desktop:~/ndnndnndn/ndn-cxx$ ./waf
Waf: Entering directory `/home/tan/ndnndnndn/ndn-cxx/build'
Waf: Leaving directory `/home/tan/ndnndnndn/ndn-cxx/build'
Traceback (most recent call last):
  File "/home/tan/ndnndnndn/ndn-cxx/.waf-1.8.9-849024857bd41c3cf8e87dc01ecf79b0/waflib/Scripting.py", line 103, in waf_entry_point
    run_commands()
  File "/home/tan/ndnndnndn/ndn-cxx/.waf-1.8.9-849024857bd41c3cf8e87dc01ecf79b0/waflib/Scripting.py", line 164, in run_commands
    ctx=run_command(cmd_name)
  File "/home/tan/ndnndnndn/ndn-cxx/.waf-1.8.9-849024857bd41c3cf8e87dc01ecf79b0/waflib/Scripting.py", line 155, in run_command
    ctx.execute()
  File "/home/tan/ndnndnndn/ndn-cxx/.waf-1.8.9-849024857bd41c3cf8e87dc01ecf79b0/waflib/Scripting.py", line 366, in execute
    return execute_method(self)
  File "/home/tan/ndnndnndn/ndn-cxx/.waf-1.8.9-849024857bd41c3cf8e87dc01ecf79b0/waflib/Build.py", line 106, in execute
    self.execute_build()
  File "/home/tan/ndnndnndn/ndn-cxx/.waf-1.8.9-849024857bd41c3cf8e87dc01ecf79b0/waflib/Build.py", line 113, in execute_build
    self.compile()
  File "/home/tan/ndnndnndn/ndn-cxx/.waf-1.8.9-849024857bd41c3cf8e87dc01ecf79b0/waflib/Build.py", line 176, in compile
    self.producer.start()
  File "/home/tan/ndnndnndn/ndn-cxx/.waf-1.8.9-849024857bd41c3cf8e87dc01ecf79b0/waflib/Runner.py", line 170, in start
    self.refill_task_list()
  File "/home/tan/ndnndnndn/ndn-cxx/.waf-1.8.9-849024857bd41c3cf8e87dc01ecf79b0/waflib/Runner.py", line 98, in refill_task_list
    self.outstanding.extend(self.biter.next())
  File "/home/tan/ndnndnndn/ndn-cxx/.waf-1.8.9-849024857bd41c3cf8e87dc01ecf79b0/waflib/Build.py", line 407, in get_build_iterator
    self.post_group()
  File "/home/tan/ndnndnndn/ndn-cxx/.waf-1.8.9-849024857bd41c3cf8e87dc01ecf79b0/waflib/Build.py", line 391, in post_group
    f()
  File "/home/tan/ndnndnndn/ndn-cxx/.waf-1.8.9-849024857bd41c3cf8e87dc01ecf79b0/waflib/TaskGen.py", line 110, in post
    v()
  File ".waf-tools/sphinx_build.py", line 60, in apply_sphinx
    confData = imp.load_source('sphinx_conf', conf.abspath())
  File "/home/tan/ndnndnndn/ndn-cxx/docs/conf.py", line 47, in <module>
    addExtensionIfExists('sphinxcontrib.doxylink')
  File "/home/tan/ndnndnndn/ndn-cxx/docs/conf.py", line 39, in addExtensionIfExists
    __import__(extension)
  File "/home/tan/.local/lib/python2.7/site-packages/sphinxcontrib/doxylink/__init__.py", line 1, in <module>
    from .doxylink import setup
  File "/home/tan/.local/lib/python2.7/site-packages/sphinxcontrib/doxylink/doxylink.py", line 170
    def find_url2(mapping, symbol: str) -> dict:
                                 ^
SyntaxError: invalid syntax</pre><pre>tan@tan-desktop:~/ndnndnndn/ndn-cxx$ </pre></blockquote><font face="monospace"><span style="white-space: pre-wrap;"><br></span></font><div><font face="monospace"><span style="white-space: pre-wrap;">Can someone guide me on this. Thank you in advance.</span></font></div>