When running step 1 of Release.txt, we get abunch of warnings like:

../roundup/cgi/client.py:1430: warning: 'msgid' format string with 
unnamed arguments cannot be properly localized:
                      The translator cannot reorder the arguments.
                      Please consider using a format string with named 
arguments,
                      and a mapping instead of a tuple for the 
arguments.
 
which points to:

  logger.error(
     self._("Csrf mismatch user: current session %s != stored session 
%s, current user/stored user is: %s for key %s."),
        current_session, nonce_session, current_user, key)

It makes it easier for translators if written as:

     self._("Csrf mismatch user: current session %(current_session)s != 
stored session %(nonce_session)s, current user/stored user is: %
(current_user)s for key %(key)s."),
        {"current_session": current_session,
         "nonce_session": nonce_session,
         "current_user": current_user, "key": key})

or, if the arguments are simple variables in local scope
(as opposed to function calls etc.)

     self._("Csrf mismatch user: current session %(current_session)s != 
stored session %(nonce_session)s, current user/stored user is: %
(current_user)s for key %(key)s."), locals())

Most important for translation are user facing strings. Second most 
important are admin facing (which includes logging at warning or 
higher.) Third are tracing statements at info or lower.