5. Import milestones...
  inserting milestone '+60'
Traceback (most recent call last):
  File "bugzilla2trac.py", line 876, in ?
    main()
  File "bugzilla2trac.py", line 873, in main
    convert(BZ_DB, BZ_HOST, BZ_USER, BZ_PASSWORD, TRAC_ENV, TRAC_CLEAN)
  File "bugzilla2trac.py", line 575, in convert
    trac.setMilestoneList(milestones, 'value')
  File "bugzilla2trac.py", line 306, in setMilestoneList
    (milestone.encode('utf-8')))
TypeError: not all arguments converted during string formatting