odt2docbook and odt2xml fail if line numbering is active. This the
attached simple testcase:

cventin:~> odt2docbook test.odt
/bin/odt2docbook:778: DeprecationWarning: distutils Version classes are deprecated. Use packaging.version instead.
  if product.ooName not in ('LibreOffice', 'LOdev') or LooseVersion(product.ooSetupVersion) <= LooseVersion('3.3'):
Entity: line 3: parser error : Attribute style:writing-mode redefined
:font-size-complex="12pt" style:language-complex="hi" style:country-complex="IN"
                                                                               ^
Traceback (most recent call last):
  File "/bin/odt2docbook", line 1037, in convert
    document.storeToURL(outputurl, tuple(outputprops) )
uno.com.sun.star.io.IOException: SfxBaseModel::impl_store <file:///home/vlefevre/test.xml> failed: 0xc10(Error Area:Io Class:Write Code:16)

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/bin/odt2docbook", line 1282, in <module>
    main()
  File "/bin/odt2docbook", line 1198, in main
    convertor.convert(inputfn)
  File "/bin/odt2docbook", line 1039, in convert
    raise UnoException("Unable to store document to %s (ErrCode %d)\n\nProperties: %s" % (outputurl, e.ErrCode, outputprops), None)
                                                                                                     ^^^^^^^^^
  File "/usr/lib/python3/dist-packages/uno.py", line 507, in _uno_struct__getattr__
    return getattr(self.__dict__["value"], name)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
AttributeError: ErrCode

and a soffice.bin process is left behind, which makes LibreOffice
unusable.

Disabling line numbering in the .odt file makes the issue disappear.