Comment 0 for bug 1067942

Converting to a book to .mobi, I get an error with this traceback:
Traceback (most recent call last):
  File "/usr/bin/calibre-parallel", line 20, in <module>
    sys.exit(main())
  File "/usr/lib/calibre/calibre/utils/ipc/worker.py", line 186, in main
    result = func(*args, **kwargs)
  File "/usr/lib/calibre/calibre/gui2/convert/gui_conversion.py", line 31, in gui_convert_override
    override_input_metadata=True)
  File "/usr/lib/calibre/calibre/gui2/convert/gui_conversion.py", line 25, in gui_convert
    plumber.run()
  File "/usr/lib/calibre/calibre/ebooks/conversion/plumber.py", line 1040, in run
    from calibre.ebooks.oeb.transforms.flatcss import CSSFlattener
  File "/usr/lib/calibre/calibre/ebooks/oeb/transforms/flatcss.py", line 19, in <module>
    from calibre.ebooks.oeb.stylizer import Stylizer
  File "/usr/lib/calibre/calibre/ebooks/oeb/stylizer.py", line 23, in <module>
    from lxml.cssselect import css_to_xpath, ExpressionError, SelectorSyntaxError
ImportError: cannot import name css_to_xpath

Looking at cssselect.py from lxml, it was converted to a wrapper for Python's CSSSelect in version 3.0.