AttributeError: 'TracError' object has no attribute 'replace'

[vokiel@…]

2016-03-03 10:53:37,105 Trac[main] WARNING: [X.X.X.X] HTTPForbidden: 403 Forbidden (TICKET_CREATE privileges are required to perform this operation on Ticket #None. You don't have the required permissions.)
2016-03-03 10:54:02,135 Trac[main] ERROR: Internal Server Error:
Traceback (most recent call last):
  File "build/bdist.linux-x86_64/egg/trac/web/main.py", line 534, in _dispatch_request
    dispatcher.dispatch(req)
  File "build/bdist.linux-x86_64/egg/trac/web/main.py", line 227, in dispatch
    resp = chosen_handler.process_request(req)
  File "build/bdist.linux-x86_64/egg/trac/timeline/web_ui.py", line 117, in process_request
    add_warning(req, e)
  File "build/bdist.linux-x86_64/egg/trac/web/chrome.py", line 199, in add_warning
    msg = escape(msg, False)
  File "/opt/python2.7/lib/python2.7/site-packages/Genshi-0.7-py2.7-linux-x86_64.egg/genshi/core.py", line 519, in escape
    text = text.replace('&', '&') \
AttributeError: 'TracError' object has no attribute 'replace'

System Information
Package	Version
Trac 	1.0.6post2
Docutils 	0.12
Genshi 	0.7 (without speedups)
mod_wsgi 	3.3 (WSGIProcessGroup site-xxx WSGIApplicationGroup %{GLOBAL})
psycopg2 	2.4.5
Pygments 	2.1.1
Python 	2.7.3 (default, May 16 2012, 10:41:38) [GCC 4.1.2 20080704 (Red Hat 4.1.2-52)]
setuptools 	0.6c11
Subversion 	1.7.14 (r1542130)
jQuery	1.7.2
jQuery UI	1.8.21
jQuery Timepicker	1.0.1

[cboos]

​WrongTrac, this should be reported on trac.edgewall.org, provided it's not a duplicate.

And it is... please see ​#T12285.