diff -Naur a/llvm/docs/conf.py b/llvm/docs/conf.py
--- a/llvm/docs/conf.py	2020-09-15 09:12:24.318287611 +0000
+++ b/llvm/docs/conf.py	2020-09-15 15:01:00.025893199 +0000
@@ -36,20 +36,7 @@
     '.rst': 'restructuredtext',
 }
 
-try:
-  import recommonmark
-except ImportError:
-  # manpages do not use any .md sources
-  if not tags.has('builder-man'):
-    raise
-else:
-  import sphinx
-  if sphinx.version_info >= (3, 0):
-    # This requires 0.5 or later.
-    extensions.append('recommonmark')
-  else:
-    source_parsers = {'.md': 'recommonmark.parser.CommonMarkParser'}
-  source_suffix['.md'] = 'markdown'
+import sphinx
 
 # The encoding of source files.
 #source_encoding = 'utf-8-sig'