Why is debug output in message pane different from terminal

[Jean-Marc Lasgouttes]

Le 25/02/2021 à 07:30, Stephan Witt a écrit :
> Am 25.02.2021 um 00:31 schrieb Richard Kimberly Heck <rikiheck at lyx.org>:
>>
>> On 2/24/21 4:03 PM, Stephan Witt wrote:
>>> Hi all,
>>>
>>> while trying to understand bug #11013 I have a problem with message pane output.
>>>
>>> The output is as follows:
>>>
>>> frontends/qt/GuiApplication.cpp (2329): action first set to []
>>>
>>> The corresponding debugger terminal output is:
>>>
>>> frontends/qt/GuiApplication.cpp (2329): action first set to [dialog-toggle]

Is it better after 5d8f3a93077 ? I would not say it is 100% satisfying, 
but I am not C++-savvy enough to understand why the << operator does not 
work (or why it works sometimes, actually). I did try to implement 
operator<<(ostream,FuncCode), but it did not change anything.

JMarc