PyGments: Failed to highlight content when web server is rendering another page in the same time

There is a problem with code macro: it is not reliable. It is not hard to see this bug. The stack trace is:

org.xwiki.rendering.macro.MacroExecutionException: Failed to highlight content
at org.xwiki.rendering.internal.macro.code.CodeMacro.parseContent(CodeMacro.java:108)
at org.xwiki.rendering.internal.macro.code.CodeMacro.parseContent(CodeMacro.java:48)
...
Caused by: Traceback (most recent call last):
File "<string>", line 1, in <module>
NameError: name 'listener' is not defined

at org.python.core.PyException.fillInStackTrace(PyException.java:70)
at java.lang.Throwable.<init>(Throwable.java:181)

I've run 4 wget requests in parallel and there was just 1 properly rendered page. I guess, PyGments rendering can only happen in 1 thread in time.

The traces of this issue can be found in different X-Wiki instances on the web, even on XWiki.org:

http://webcache.googleusercontent.com/search?q=cache:3CuubATVEtgJ:extensions.xwiki.org/xwiki/bin/view/Extension/Date%2BPicker%2BApplication+name+'listener'+is+not+defined+org.python.core&cd=2&hl=ru&ct=clnk&gl=ru&client=safari&source=www.google.ru

I suggest migrating to Jgments as an option