我正在尝试从源代码安装ROS。
当我执行安装命令时，出现这样的错误：
Traceback (most recent call last):
File "/home/zyh/ros_catkin_ws/install_isolated/share/ros/core/rosbuild/bin/download_checkmd5.py", line 126, in <module>
sys.exit(main())
File "/home/zyh/ros_catkin_ws/install_isolated/share/ros/core/rosbuild/bin/download_checkmd5.py", line 73, in main
urllib.urlretrieve('https://github.com/assimp/assimp/archive/v3.1.1.zip', dest)
File "/usr/lib/python2.7/urllib.py", line 98, in urlretrieve
return opener.retrieve(url, filename, reporthook, data)
File "/usr/lib/python2.7/urllib.py", line 245, in retrieve
fp = self.open(url, data)
File "/usr/lib/python2.7/urllib.py", line 213, in open
return getattr(self, name)(url)
File "/usr/lib/python2.7/urllib.py", line 443, in open_https
h.endheaders(data)
File "/usr/lib/python2.7/httplib.py", line 1038, in endheaders
self._send_output(message_body)
File "/usr/lib/python2.7/httplib.py", line 882, in _send_output
self.send(msg)
File "/usr/lib/python2.7/httplib.py", line 844, in send
self.connect()
File "/usr/lib/python2.7/httplib.py", line 1263, in connect
server_hostname=server_hostname)
File "/usr/lib/python2.7/ssl.py", line 363, in wrap_socket
_context=self)
File "/usr/lib/python2.7/ssl.py", line 611, in __init__
self.do_handshake()
File "/usr/lib/python2.7/ssl.py", line 840, in do_handshake
self._sslobj.do_handshake()
IOError: [Errno socket error] [SSL: UNKNOWN_PROTOCOL] unknown protocol (_ssl.c:661)
/home/zyh/ros_catkin_ws/install_isolated/share/mk/download_unpack_build.mk:37: recipe for target 'build/assimp-3.1.1/unpacked' failed
make[3]: *** [build/assimp-3.1.1/unpacked] Error 1
我不知道如何解决这个问题。也许是因为我在代理后面工作？如果是这样，如何使
urllib.urlretrieve在代理后面工作？ 最佳答案
将代理设置添加到您的全局环境，以查看是否可以解决问题。
sudo gedit /etc/environment
然后添加这两行
http_proxy=http://your_proxy.com:443
https_proxy=https://your_proxy.com:443
关于python - python2.7:[SSL:UNKNOWN_PROTOCOL]未知协议(protocol)，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/49050788/