Supervisor: Can not start supervisord

[baiyuxiong]

supervisord

Traceback (most recent call last):
File "/usr/bin/supervisord", line 5, in
from pkg_resources import load_entry_point
File "/usr/local/lib/python2.7/site-packages/pkg_resources/__init__.py", line 3019, in
@_call_aside
File "/usr/local/lib/python2.7/site-packages/pkg_resources/__init__.py", line 3003, in _call_aside
f(args, *kwargs)
File "/usr/local/lib/python2.7/site-packages/pkg_resources/__init__.py", line 3032, in _initialize_master_working_set
working_set = WorkingSet._build_master()
File "/usr/local/lib/python2.7/site-packages/pkg_resources/__init__.py", line 657, in _build_master
return cls._build_from_requirements(__requires__)
File "/usr/local/lib/python2.7/site-packages/pkg_resources/__init__.py", line 670, in _build_from_requirements
dists = ws.resolve(reqs, Environment())
File "/usr/local/lib/python2.7/site-packages/pkg_resources/__init__.py", line 849, in resolve
raise DistributionNotFound(req, requirers)
pkg_resources.DistributionNotFound: The 'supervisor==3.1.3' distribution was not found and is required by the application

Re-install, no error :

pip install supervisor

Collecting supervisor
Requirement already satisfied: meld3>=0.6.5 in /usr/local/lib/python2.7/site-packages (from supervisor)
Installing collected packages: supervisor
Successfully installed supervisor-3.3.1

python -V

Python 2.7.13

[mnaberez]

Please ask questions about installing or using Supervisor on the supervisor-users mailing list. We use this issue tracker mainly for bugs in Supervisor itself.

[BigAlone]

This is my error.Why can I run it from someone else's version?Please
Collecting supervisor
Using cached https://files.pythonhosted.org/packages/44/60/698e54b4a4a9b956b2d709b4b7b676119c833d811d53ee2500f1b5e96dc3/supervisor-3.3.4.tar.gz
Complete output from command python setup.py egg_info:
Supervisor requires Python 2.4 or later but does not work on any version of Python 3. You are using version 3.6.5 (default, May 3 2018, 10:08:28)
[GCC 5.4.0 20160609]. Please install using a supported version.