How to remove TypeError: '>=' not supported between instances of 'NoneType' and 'str'?

Question

Python

Please tell me how to solve this problem when installing kivent modules, namely core.
I run these options on the command line: python setup.py build_ext install
Before this error, there was an error: Unable to find vcvarsall.bat - it was cured by installing visual studio 2015
I get this error:

[INFO   ] [Logger      ] Record log in C:\Users\User\.kivy\logs\kivy_18-10-09_4.txt
[INFO   ] [Kivy        ] v1.10.1
[INFO   ] [Python      ] v3.6.6 (v3.6.6:4cf1f54eb7, Jun 27 2018, 03:37:03) [MSC v.1900 64 bit (AMD64)]
Using distutils
running build_ext
 Traceback (most recent call last):
   File "setup.py", line 212, in <module>
     'uix/*.pxd'
   File "C:\Users\User\AppData\Local\Programs\Python\Python36\lib\distutils\core.py", line 148, in setup
     dist.run_commands()
   File "C:\Users\User\AppData\Local\Programs\Python\Python36\lib\distutils\dist.py", line 955, in run_commands
     self.run_command(cmd)
   File "C:\Users\User\AppData\Local\Programs\Python\Python36\lib\distutils\dist.py", line 974, in run_command
     cmd_obj.run()
   File "C:\Users\User\AppData\Local\Programs\Python\Python36\lib\distutils\command\build_ext.py", line 308, in run
     force=self.force)
   File "C:\Users\User\AppData\Local\Programs\Python\Python36\lib\distutils\ccompiler.py", line 1031, in new_compiler
     return klass(None, dry_run, force)
   File "C:\Users\User\AppData\Local\Programs\Python\Python36\lib\distutils\cygwinccompiler.py", line 282, in __init__
     CygwinCCompiler.__init__ (self, verbose, dry_run, force)
   File "C:\Users\User\AppData\Local\Programs\Python\Python36\lib\distutils\cygwinccompiler.py", line 126, in __init__
     if self.ld_version >= "2.10.90":
 TypeError: '>=' not supported between instances of 'NoneType' and 'str'