diff --git a/sphinx/ext/autodoc.py b/sphinx/ext/autodoc.py
index 825c63ff8..45dbdcdb4 100644
--- a/sphinx/ext/autodoc.py
+++ b/sphinx/ext/autodoc.py
@@ -717,7 +717,8 @@ class Documenter(object):
             # parse right now, to get PycodeErrors on parsing (results will
             # be cached anyway)
             self.analyzer.find_attr_docs()
-        except PycodeError:
+        except PycodeError, err:
+            self.env.app.debug('[autodoc] module analyzer failed: %s', err)
             # no source file -- e.g. for builtin and C modules
             self.analyzer = None
             # at least add the module.__file__ as a dependency