---
features:
  - |
    If the log format string includes ``%(error_summary)s``, it will
    be replaced with a summary of the current error when there is one
    and with "``-``" when there is no error.  If the log format string
    does not include ``%(error_summary)s`` the error summary will be
    appended to the end of the line automatically, only if there is an
    error.