The problem is a "datetime.datetime <-> int comparision error" because:
1. The default date-format of the ISearchSource is datetime
2. DoxygenPlugin returns the filedate (ctime) as int.
3. Trac compares both time-types to sort them, but fails because type datetime can not be compared with type int.
Here are the patch instructions for doxygentrac.py using the trac function to_datetime:
...
from trac.util.datefmt import to_timestamp, to_datetime, utc
...
def get_search_results(self, req, keywords, filters):
...
if os.path.isdir(path):
index = os.path.join(path, 'search.idx')
if os.path.exists(index):
>>>> creation = to_datetime(os.path.getctime(index)) <<<<
for result in self._search_in_documentation(doc, keywords):
result['url'] = req.href.doxygen(doc) + '/' \
...
if os.path.exists(index):
>>>> creation = to_datetime(os.path.getctime(index)) <<<<
for result in self._search_in_documentation('', keywords):