How to enable wxLogMessage output?

[robert-dodier]

I see that src/wxMaxima.cpp has a number of calls to wxLogMessage and it seems like it would be very useful for debugging if those could be enabled to output to the console or a file or something.

However on looking at the command line options and inspecting the source code, I don't see a way to do that.

How can I enable wxLogMessage output by any means, whether it be to the console, to a file, or to a pop up window?

Ideally it would be possible to enable wxLogMessage output by a command line option; however, if it is necessary to rebuild wxMaxima to enable it, please say exactly what is needed -- I just need to know how to do it, and then I will figure out what to do.

[daute]

You can see the log messages in the "Debug messages" sidebar ("View" -> "Sidebars" -> "Debug messages" to enable it).
And there is a --logtostderr command line option, which will print the log messages to the console (standard error output).

Note: In older versions of wxMaxima the command line option was called --logtostdout (which was wrong, because the log messages go to stderr). This was changed with commit 492ae18.

[robert-dodier]

Hmm, I see a few messages in the "Debug messages" sidebar. For the record,

09:15:44 AM: wxMaxima version 24.08.0_DevelopmentSnapshot
09:15:44 AM: OS: Linux 4.15.0-142-generic x86_64 Version 4.15
09:15:44 AM: wxWidgets 3.2.4
09:15:44 AM: wxWidgets is using GTK 3
09:15:44 AM: Reading the config from the default location.
09:15:45 AM: Caching font variant: Ubuntu 12
09:15:45 AM: Caching font variant: Ubuntu Bold 12
09:15:45 AM: Instructed to prefer gnuplot over wgnuplot
09:15:45 AM: Gnuplot found at: gnuplot

and then no additional messages are displayed as I try various operations such as opening a worksheet or restarting Maxima.

I see a number of wxLogMessage calls in src/wxMaxima.cpp, so I wonder why they are not being displayed. Some of them appear to be warning messages that occur only in special circumstances, but some of them are just general informational messages, e.g. wxMaxima::SetCWD which is called from several places such as opening or saving a worksheet.

I see wxLog;:SetActiveTarget(new NullLog) in various places; maybe logging is mostly disabled?

Is there a way to set the logging output level, e.g. verbose / nonverbose ?

[robert-dodier]

I see that some of the NullLog stuff was introduced in commit ed6f4c8. @gunterkoenigsmann Does this bit

@@ -203,6 +204,7 @@ wxMaxima::wxMaxima(wxWindow *parent, int id,
   wxLogMessage(_("Will try to generate a stack backtrace, if the program ever crashes"));
 #endif 
   GnuplotCommandName(wxS("gnuplot"));
+  wxLog::SetActiveTarget(new NullLog);
   
   if (m_variableReadActions.empty()) {
     m_variableReadActions[wxS("gentranlang")] =

of commit ed6f4c8 have some specific purpose?

I find that if I remove that line, I get more messages. Is that line needed for some purpose?

[gunterkoenigsmann]

I tried to suppress debug output when closing the application as if there no longer is a log messages sidebar the log messages will appear in annoying message Dialogs.
Then I tried to suppress log messages in background threads (as long as they appear in a log sidebar that is thread-safe, but if the main thread has closed that sidebar some gui toolkits try to open dialogs from the background thread and fail.
And MacOs might refuse any further interaction if a log message appears on stderr which is why I suppress some early log messages. I might have suppressed more messages than necessary, though, as in the end I resorted to trial-and-error.

[robert-dodier]

Okay, well, it makes sense to disable logging output since it leads to errors which are difficult to resolve. As it stands, there is really only a little bit of logging output, since logging is disabled very soon after launching wxMaxima. I don't have any ideas about how to resolve the errors, so I am thinking that we can do two things:

(1) cut out existing logging to a UI pane entirely
(2) output log messages to stderr if enabled by a command line option.

What does anyone think of that?

[daute]

That is probably a good idea. For 'normal users' these log messages do not provide useful information. And in case of problems we can tell the user (and document in the manual) that wxmaxima should be started with --logtostderr to get log messages, which should be included in the bug report.

[robert-dodier]

Okay, I will take a look at changing the logging stuff. One problem that I see is that many people are going to be launching wxMaxima via a clickable button on the desktop or the Windows start menu -- I guess that to set a command line option, they would have to modify the command line associated with the launcher. That's not out of the question, but it's an additional step that probably some people are going to have trouble with. I wonder if there is anything we can do that doesn't require that. Hmm, something to think about.

[daute]

Commit 5556bb7 implemented at least the idea with the command line option --logtostderr - messages are continued on stderr, if that is enabled. And a message is logged, that the messages in the debug window are stopped.
Not optimal, but better than before.

[daute]

Maybe an idea would be that the "Debug messages" sidebar is never destroyed, but only hidden and shown using the Hide() and Show() functions.

[robert-dodier]

About hiding/showing the Debug messages sidebar, yes, that make sense to me, maybe that's something to try.