No application output in QtCreator debug

Question

With QtCreator 2.8 under Win7 with CDB debugger, I cannot see in the Application Output tab all my fprintf(stdout) stuff !?

I tried:

fprintf(stderr, "...");

fprintf(stdout, "..."); fflush(stdout);

Nothing happens. In the meantime, If I check the "Run in terminal" option, it works !?

Although I noticed that all the output go to debugger log !?

Any idea ?

Have you tried running in a terminal instead? For Qt5 + QtCreator 2.7 I have also noticed that some qDebug() print statements not showing up on the application output tab. — Son-Huy Pham, Jul 02 '13 at 18:33
Whoops i didn't read your comment about the console! but yes to reiterate - I think it's a new Qt5-ish bug! i hope it's a known issue... will have to look it up — Son-Huy Pham, Jul 02 '13 at 18:42
You should report this as a bug at: https://bugreports.qt-project.org/browse/QTCREATORBUG — Mitch, Jul 18 '13 at 07:00
Out of curiosity: Is there a reason that you use fprintf iso of qDebug()? — Kurt Pattyn, Aug 24 '13 at 12:48
Have you tried adding `CONSOLE` to the `CONFIG` variable in the .pro file? — Kurt Pattyn, Aug 24 '13 at 12:50

score 4 · Accepted Answer · answered Jul 14 '14 at 18:10

4

As a workaround you can enable the output in CDB console: tools/options/debugger/cdb then check "Use CDB console". To show the debugger, right click on some window header and select "Debugger Log". You may also right click on the debugger log view to disable the verbose log. Btw, I also noticed that the standard application output window works well when you "attach to the running process" instead of starting it from qtcreator.

answered Jul 14 '14 at 18:10

Cyrion

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Thanks for this comment. This does give you a lot of output, but not the output you expect as you run the executable from command line. – jaques-sam May 20 '19 at 15:14

Pete D. · Answer 2 · 2021-04-16T13:46:12.087

Not an answer, just a comment that this is obviously a "feature" and isn't going to get fixed.

I've just started porting a C++/Qt project that has been developed under linux with GCC and Clang, and Windows 7 with MinGW GCC, to Windows 10 with MSVC. If my test code is run as individual programs it reports "All tests passed" (or not), to the console, (std::cout) which in this case is the Qt Creator Application Output window. It has been working on all systems, with all compilers, in both debug and release mode, for years. It now doesn't write to the Application output window when run via the debugger, only if run as if it was the release version.

On discovering this (2021-04-16), I Googled for the solution, and landed here.

score 0 · Answer 3 · answered May 02 '21 at 15:50

I know that this answer do not answer the original question, but since when searching for "No application output" we found this answer...

See the following answer: https://stackoverflow.com/a/26325743/808101. This only apply to qDebug() and similar functions (not direct output to stdout/stderr). In my case, I have to set QT_ASSUME_STDERR_HAS_CONSOLE environment variable to 1 in QtCreator in order to see qDebug() messages inside "Application Output" window. For older version of Qt see linked answer for old/deprecated environment variable.

score -2 · Answer 4 · edited Nov 27 '13 at 09:43

-2

I often use qDebug this way.

#include <QDebug> in the top of the file

Usage:

qDebug() << "This is a Test";

It runs well when using QT creator and does not matter in GUI programming or Console Application.

edited Nov 27 '13 at 09:43

user2633954

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answered Aug 27 '13 at 07:51

DarkPirate

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That's irrelevant here, the problem is the output is not displayed in QtCreator no matter what you use to write it. – kralyk Jul 07 '14 at 18:05

No application output in QtCreator debug

4 Answers4

Linked