https://github.com/kmuto/review/pull/181 これを1.8.xと1.9.xで共に問題なく実行できそうなパッチ(VMの気持ちで考えたけど1.9.x試してない)

gistfile1.rb

$ git diff -p
diff --git a/lib/review/htmlutils.rb b/lib/review/htmlutils.rb
index 64ef016..514ff53 100644
--- a/lib/review/htmlutils.rb
+++ b/lib/review/htmlutils.rb
@@ -39,15 +39,19 @@ module ReVIEW
 
       begin
         require 'pygments'
-        Pygments.highlight(
-                 unescape_html(body),
-                 :options => {
-                             :nowrap => true,
-                             :noclasses => true
-                           },
-                 :formatter => format,
-                 :lexer => lexer)
-      rescue LoadError, MentosError
+        begin
+          Pygments.highlight(
+                   unescape_html(body),
+                   :options => {
+                               :nowrap => true,
+                               :noclasses => true
+                             },
+                   :formatter => format,
+                   :lexer => lexer)
+        rescue MentosError
+          body
+        end
+      rescue LoadError
         body
       end
     end