cubicweb-vcsfile #783421 InternalError: PL/Python: PL/Python function "version_data" failed [deprecated]

On a karmic install, while importing an hg repository

2010-03-24 12:02:57 - (cubicweb.sources.system) CRITICAL: sql: 'SELECT VERSION_DATA(_X.cw_eid)\nFROM cw_VersionContent AS _X\nWHERE _X.cw_eid=%(x)s'
 args: {'x': 884}
dbms message: 'PL/Python: PL/Python function "version_data" failed\nDETAIL:  <type \'exceptions.ImportError\'>: No module named cubes\n'
2010-03-24 12:02:57 - (cubicweb.sources.system) CRITICAL: transaction has been rollbacked
2010-03-24 12:02:57 - (cubicweb.repository) ERROR: unexpected error
Traceback (most recent call last):
File "/home/arthur/src/public/cubicweb/cubicweb/server/repository.py", line 582, in execute
  build_descr)
File "/home/arthur/src/public/cubicweb/cubicweb/server/querier.py", line 659, in execute
  results = plan.execute()
File "/home/arthur/src/public/cubicweb/cubicweb/server/querier.py", line 172, in execute
  result = step.execute()
File "/home/arthur/src/public/cubicweb/cubicweb/server/ssplanner.py", line 286, in execute
  inputmap)
File "/home/arthur/src/public/cubicweb/cubicweb/server/sources/native.py", line 323, in syntax_tree_search
  cursor = self.doexec(session, sql, args)
File "/home/arthur/src/public/cubicweb/cubicweb/server/sources/native.py", line 437, in doexec
  cursor.execute(str(query), args)
InternalError: PL/Python: PL/Python function "version_data" failed
DETAIL:  <type 'exceptions.ImportError'>: No module named cubes
prioritynormal
typebug
done in<not specified>
load0.000
load left0.000
closed by<not specified>