Trac 1.4 incompatiblity

[anonymous]

The plugin cannot be installed in Trac 1.4, it crashes the application with error in log

2019-10-08 15:34:15,658 Trac[main] ERROR: Internal Server Error: <RequestWithSession "GET '/wiki/Home'">, referrer ''redacted''
Traceback (most recent call last):
  File "/var/lib/trac/trac14/lib/python2.7/site-packages/Trac-1.4-py2.7.egg/trac/web/main.py", line 639, in dispatch_request
    dispatcher.dispatch(req)
  File "/var/lib/trac/trac14/lib/python2.7/site-packages/Trac-1.4-py2.7.egg/trac/web/main.py", line 271, in dispatch
    method=method)
  File "/var/lib/trac/trac14/lib/python2.7/site-packages/Trac-1.4-py2.7.egg/trac/web/chrome.py", line 1441, in render_template
    fragment, iterable, method)
  File "/var/lib/trac/trac14/lib/python2.7/site-packages/Trac-1.4-py2.7.egg/trac/web/chrome.py", line 1516, in _render_jinja_template
    page = self.render_template_string(template, data, text)
  File "/var/lib/trac/trac14/lib/python2.7/site-packages/Trac-1.4-py2.7.egg/trac/web/chrome.py", line 1675, in render_template_string
    string = template.render(data)
  File "/var/lib/trac/trac14/lib/python2.7/site-packages/Jinja2-2.10.3-py2.7.egg/jinja2/environment.py", line 1008, in render
    return self.environment.handle_exception(exc_info, True)
  File "/var/lib/trac/trac14/lib/python2.7/site-packages/Jinja2-2.10.3-py2.7.egg/jinja2/environment.py", line 780, in handle_exception
    reraise(exc_type, exc_value, tb)
  File "/var/lib/trac/trac14/lib/python2.7/site-packages/Trac-1.4-py2.7.egg/trac/wiki/templates/wiki_view.html", line 11, in top-level template code
    # extends 'layout.html'
  File "/var/lib/trac/trac14/lib/python2.7/site-packages/Trac-1.4-py2.7.egg/trac/templates/layout.html", line 12, in top-level template code
    # import "macros.html" as jmacros with context
  File "/var/lib/trac/BikeTrackLogger/.egg-cache/BlueFlatTheme-1.0.1-py2.7.egg-tmp/blueflattheme/templates/blueflat_theme.html", line 12, in top-level template code
    ${select('*|comment()|text()')}
UndefinedError: 'select' is undefined