better error reporting when doc parsing fails

lib/ansible/cli/doc.py

@@ -81,6 +81,7 @@ class DocCLI(CLI):
         text = ''
         for module in self.args:
 
+            try:
                 filename = module_loader.find_plugin(module)
                 if filename is None:
                     self.display.warning("module %s not found in %s\n" % (module, DocCLI.print_paths(module_loader)))
@@ -117,7 +118,9 @@ class DocCLI(CLI):
                 else:
                     # this typically means we couldn't even parse the docstring, not just that the YAML is busted,
                     # probably a quoting issue.
-                self.display.warning("module %s missing documentation (or could not parse documentation)\n" % module)
+                    raise AnsibleError("Parsing produced an empty object.")
+            except Exception, e:
+                raise AnsibleError("module %s missing documentation (or could not parse documentation): %s\n" % (module, str(e)))
 
         CLI.pager(text)
         return 0