生信分析 在Ubuntu 当中出现错误 so: undefined symbol: PyUnicodeUCS2_FromStringAndSize 应该如何解决

Ubuntu 当中调用python写的一个软件CrossMap.py,但是出现错误 so: undefined symbol: PyUnicodeUCS2_FromStringAndSize
代码如下 :
root@LAPTOP-PBJPC2EI:/home/yuling/try0606# CrossMap.py
Traceback (most recent call last):
File "/usr/local/bin/CrossMap.py", line 4, in
import('pkg_resources').run_script('CrossMap==0.2.5', 'CrossMap.py')
File "/usr/lib/python2.7/dist-packages/pkg_resources/init.py", line 658, in run_script
self.require(requires)[0].run_script(script_name, ns)
File "/usr/lib/python2.7/dist-packages/pkg_resources/init.py", line 1438, in run_script
exec(code, namespace, namespace)
File "/usr/local/lib/python2.7/dist-packages/CrossMap-0.2.5-py2.7.egg/EGG-INFO/scripts/CrossMap.py", line 23, in
from bx.bbi.bigwig_file import BigWigFile
ImportError: /usr/local/lib/python2.7/dist-packages/bx/bbi/bigwig_file.so: undefined symbol: PyUnicodeUCS2_FromStringAndSize

应该怎么解决呢?