Seeing Warning: Error with navigation contributor "PreferencesModule" in browser

[Adrian Heath]

Upgraded from Trac 0.12/python 2.6 to Trac 1.2.3/python 2.7.

When building and installing DynamicFields from trunk, seeing following message in browser:-

Warning: Error with navigation contributor "PreferencesModule"

trac.log reporting

2019-07-12 10:56:31,871 Trac[chrome] ERROR: Error with navigation contributor PreferencesModule:
Traceback (most recent call last):
  File "/usr/lib/python2.7/dist-packages/trac/web/chrome.py", line 826, in prepare_request
    contributor.get_navigation_items(req) or []:
  File "/usr/lib/python2.7/dist-packages/trac/prefs/web_ui.py", line 48, in get_navigation_items
    panels = self._get_panels(req)[0]
  File "/usr/lib/python2.7/dist-packages/trac/prefs/web_ui.py", line 138, in _get_panels
    p = list(provider.get_preference_panels(req) or [])
  File "build/bdist.linux-x86_64/egg/dynfields/web_ui.py", line 61, in get_preference_panels
    if self._get_prefs_data(req):  # only show if there are preferences
  File "build/bdist.linux-x86_64/egg/dynfields/web_ui.py", line 101, in _get_prefs_data
    rule.update_pref(req, trigger, target, key, opts, pref)
  File "build/bdist.linux-x86_64/egg/dynfields/rules.py", line 330, in update_pref
    trigval = spec['trigger_value'].replace('|', _(" or "))
UnboundLocalError: local variable '_' referenced before assignment

[Ryan J Ollos]

Looks like a regression in r13689.

[Ryan J Ollos]

In 17416:

TracDynamicFields 2.3.0dev: Fix regression in r13689.

Refs #13573.

[Adrian Heath]

Thank you for your timely update.

That was the only issue we had upgrading Trac + plugins from v0.12 to v1.2.