Debian Squeeze recently pushed out an update which appears to break xapian 
indexing in roundup with the tip of the traceback reporting:

  File "/usr/local/lib/python2.6/dist-
packages/roundup/backends/indexer_xapian.py", line 123, in find
    for m in matches]
TypeError: 'MSetItem' object does not support indexing

The xapian version in squeeze is 1.2.3-2 and python-xapian is 1.2.3-3.

No relevant debian bugs appear to be reported against these packages 
suggesting an API change (in xapian or python-xapian) which is 
incompatible with roundup. A clue is a similar breakage in Debian's 
software-center package which also uses xapian via python.

http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=596079 

The bottom line is that indexing and text search in roundup is broken in 
(my) squeeze hosted 1.4 tracker and I'm not sure whether anything needs to 
be done in roundup to fix it (ie. for an xapian API change) or whether 
it's just a bug in the xapian or python-xapian packages which will be 
fixed eventually.

Any thoughts?