Fixed #3821: Failed to import sphinx.util.compat with docutils-0.14rc1

CHANGES

@@ -16,6 +16,8 @@ Features added
 Bugs fixed
 ----------
 
+* #3821: Failed to import sphinx.util.compat with docutils-0.14rc1
+
 Testing
 --------
 

sphinx/util/compat.py

@@ -12,13 +12,14 @@ from __future__ import absolute_import
 
 import sys
 import warnings
+from distutils.version import LooseVersion
 
 from docutils.parsers.rst import Directive  # noqa
 from docutils import __version__ as _du_version
 
 from sphinx.deprecation import RemovedInSphinx17Warning
 
-docutils_version = tuple(int(x) for x in _du_version.split('.')[:2])
+docutils_version = tuple(LooseVersion(_du_version).version)[:2]
 
 if False:
     # For type annotation