我根据GitHub上的安装说明在Ubuntu14.04上安装了portia2，一切顺利。但是当我使用slyd/bin/slyd -p 9002 -r portiaui/dist & portia_server/manage.py runserver运行portia时，发生了以下错误：
Successfully installed slybot
python@ubuntu:~/Desktop/portia2/portia$
PYTHONPATH='/vagrant/portia_server:/vagrant/slyd:/vagrant/slybot'
python@ubuntu:~/Desktop/portia2/portia$ slyd/bin/slyd -p 9002 -r
portiaui/dist &[1] 10526
python@ubuntu:~/Desktop/portia2/portia$ portia_server/manage.py
runserver2017-09-19 00:42:27-0700 [-] Log opened.
2017-09-19 00:42:27.135148 [-] Splash version: 2.3.3
2017-09-19 00:42:27.159967 [-] WARNING: Lua scripting is not available
because 'lupa' Python package is not installed
2017-09-19 00:42:27.160091 [-] Qt 5.5.1, PyQt 5.5.1, WebKit 538.1, sip 4.17,
Twisted 16.1.1
2017-09-19 00:42:27.160236 [-] Python 2.7.6 (default, Oct 26 2016, 20:30:19)
[GCC 4.8.4]
2017-09-19 00:42:27.160299 [-] Open files limit: 1024
2017-09-19 00:42:27.160345 [-] Open files limit increased from 1024 to 4096
2017-09-19 00:42:27.297087 [-] Xvfb is started: ['Xvfb', ':831598118', '-
screen', '0', '1024x768x24', '-nolisten', 'tcp']
Xlib: extension "RANDR" missing on display ":831598118".
2017-09-19 07:42:35.659210 [-] Traceback (most recent call last):
2017-09-19 07:42:35.659549 [-] File "slyd/bin/slyd", line 34, in <module>
2017-09-19 07:42:35.659750 [-]
splash.server.main(server_factory=make_server, argv=[])
2017-09-19 07:42:35.659915 [-] File "/usr/local/lib/python2.7/dist-
packages/splash/server.py", line 372, in main
2017-09-19 07:42:35.660109 [-] server_factory=server_factory,
2017-09-19 07:42:35.660267 [-] File "/usr/local/lib/python2.7/dist-
packages/splash/server.py", line 291, in default_splash_server
2017-09-19 07:42:35.660448 [-]
argument_cache_max_entries=argument_cache_max_entries,
2017-09-19 07:42:35.660582 [-] File "slyd/bin/slyd", line 31, in
make_server
2017-09-19 07:42:35.660749 [-] 'docroot': opts.root}))
2017-09-19 07:42:35.660895 [-] File
"/home/python/Desktop/portia2/portia/slyd/slyd/tap.py", line 88, in
makeService
2017-09-19 07:42:35.661046 [-] root = create_root(config,
settings_module)
2017-09-19 07:42:35.661175 [-] File
"/home/python/Desktop/portia2/portia/slyd/slyd/tap.py", line 61, in
create_root
2017-09-19 07:42:35.661350 [-] for file_name in
listdir(config['docroot']):
2017-09-19 07:42:35.661495 [-] OSError: [Errno 2] No such file or directory:
'portiaui/dist'
我需要做些什么来解决这个问题？