[6.8.1] fail2ban failed to start

after 6.8.1 update fail2ban failed to start:

root@Tower:/custom/fail2ban-0.11.1# /etc/rc.d/rc.fail2ban start
Starting fail2ban:
ERROR:root:code for hash md5 was not found.
Traceback (most recent call last):
  File "/usr/lib64/python2.7/hashlib.py", line 139, in <module>
    globals()[__func_name] = __get_hash(__func_name)
  File "/usr/lib64/python2.7/hashlib.py", line 91, in __get_builtin_constructor
    raise ValueError('unsupported hash type ' + name)
ValueError: unsupported hash type md5
ERROR:root:code for hash sha1 was not found.
Traceback (most recent call last):
  File "/usr/lib64/python2.7/hashlib.py", line 139, in <module>
    globals()[__func_name] = __get_hash(__func_name)
  File "/usr/lib64/python2.7/hashlib.py", line 91, in __get_builtin_constructor
    raise ValueError('unsupported hash type ' + name)
ValueError: unsupported hash type sha1
ERROR:root:code for hash sha224 was not found.
Traceback (most recent call last):
  File "/usr/lib64/python2.7/hashlib.py", line 139, in <module>
    globals()[__func_name] = __get_hash(__func_name)
  File "/usr/lib64/python2.7/hashlib.py", line 91, in __get_builtin_constructor
    raise ValueError('unsupported hash type ' + name)
ValueError: unsupported hash type sha224
ERROR:root:code for hash sha256 was not found.
Traceback (most recent call last):
  File "/usr/lib64/python2.7/hashlib.py", line 139, in <module>
    globals()[__func_name] = __get_hash(__func_name)
  File "/usr/lib64/python2.7/hashlib.py", line 91, in __get_builtin_constructor
    raise ValueError('unsupported hash type ' + name)
ValueError: unsupported hash type sha256
ERROR:root:code for hash sha384 was not found.
Traceback (most recent call last):
  File "/usr/lib64/python2.7/hashlib.py", line 139, in <module>
    globals()[__func_name] = __get_hash(__func_name)
  File "/usr/lib64/python2.7/hashlib.py", line 91, in __get_builtin_constructor
    raise ValueError('unsupported hash type ' + name)
ValueError: unsupported hash type sha384
ERROR:root:code for hash sha512 was not found.
Traceback (most recent call last):
  File "/usr/lib64/python2.7/hashlib.py", line 139, in <module>
    globals()[__func_name] = __get_hash(__func_name)
  File "/usr/lib64/python2.7/hashlib.py", line 91, in __get_builtin_constructor
    raise ValueError('unsupported hash type ' + name)
ValueError: unsupported hash type sha512
ERROR:root:code for hash md5 was not found.
Traceback (most recent call last):
  File "/usr/lib64/python2.7/hashlib.py", line 139, in <module>
    globals()[__func_name] = __get_hash(__func_name)
  File "/usr/lib64/python2.7/hashlib.py", line 91, in __get_builtin_constructor
    raise ValueError('unsupported hash type ' + name)
ValueError: unsupported hash type md5
ERROR:root:code for hash sha1 was not found.
Traceback (most recent call last):
  File "/usr/lib64/python2.7/hashlib.py", line 139, in <module>
    globals()[__func_name] = __get_hash(__func_name)
  File "/usr/lib64/python2.7/hashlib.py", line 91, in __get_builtin_constructor
    raise ValueError('unsupported hash type ' + name)
ValueError: unsupported hash type sha1
ERROR:root:code for hash sha224 was not found.
Traceback (most recent call last):
  File "/usr/lib64/python2.7/hashlib.py", line 139, in <module>
    globals()[__func_name] = __get_hash(__func_name)
  File "/usr/lib64/python2.7/hashlib.py", line 91, in __get_builtin_constructor
    raise ValueError('unsupported hash type ' + name)
ValueError: unsupported hash type sha224
ERROR:root:code for hash sha256 was not found.
Traceback (most recent call last):
  File "/usr/lib64/python2.7/hashlib.py", line 139, in <module>
    globals()[__func_name] = __get_hash(__func_name)
  File "/usr/lib64/python2.7/hashlib.py", line 91, in __get_builtin_constructor
    raise ValueError('unsupported hash type ' + name)
ValueError: unsupported hash type sha256
ERROR:root:code for hash sha384 was not found.
Traceback (most recent call last):
  File "/usr/lib64/python2.7/hashlib.py", line 139, in <module>
    globals()[__func_name] = __get_hash(__func_name)
  File "/usr/lib64/python2.7/hashlib.py", line 91, in __get_builtin_constructor
    raise ValueError('unsupported hash type ' + name)
ValueError: unsupported hash type sha384
ERROR:root:code for hash sha512 was not found.
Traceback (most recent call last):
  File "/usr/lib64/python2.7/hashlib.py", line 139, in <module>
    globals()[__func_name] = __get_hash(__func_name)
  File "/usr/lib64/python2.7/hashlib.py", line 91, in __get_builtin_constructor
    raise ValueError('unsupported hash type ' + name)
ValueError: unsupported hash type sha512
2020-01-12 17:11:54,549 fail2ban                [15981]: ERROR   'module' object                                                        has no attribute 'sha1'
ERROR:fail2ban:'module' object has no attribute 'sha1'
2020-01-12 17:12:24,895 fail2ban                [15980]: ERROR   Could not start                                                        server. Maybe an old socket file is still present. Try to remove /var/run/fail2                                                       ban/fail2ban.sock. If you used fail2ban-client to start the server, adding the -                                                       x option will do it
ERROR:fail2ban:Could not start server. Maybe an old socket file is still present

A quick search shows that is related to python installation:

https://stackoverflow.com/questions/59269208/errorrootcode-for-hash-md5-was-not-found-not-able-to-use-any-hg-mercurial-co

https://stackoverflow.com/questions/59068580/cqlsh-errorrootcode-for-hash-md5-was-not-found

https://stackoverflow.com/questions/20399331/error-importing-hashlib-with-python-2-7-but-not-with-2-6

...

Solution:

i download and install python-2.7.17-x86_64-2.txz and fail2ban starts without problem.

I download and install python-2.7.5-x86_64-1.txz to double check and fail2ban failed to start again.

I'm not sure if there is a python update in 6.8.1 but seems like something broken in it.