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From: David Stacey <>
Subject: Cannot run Qt5 applications.
Date: Wed, 04 Feb 2015 23:20:00 -0000	[thread overview]
Message-ID: <> (raw)

[-- Attachment #1: Type: text/plain, Size: 1341 bytes --]

I'm having difficulty running any Qt5 application. These are the 
commands I'm issuing:

     XWin -multiwindow &
     export DISPLAY=:0.0
     xclock &

and I see the clock, so X is up and running. Then:

     QXcbConnection: XCB error: 145 (Unknown), sequence: 162, resource 
id: 0, major c
     ode: 140 (Unknown), minor code: 20
     Bad system call (core dumped)

and no clock.

I've tried compiling a really trivial Qt5 example (attached):

     g++ -I/usr/include/qt5 -I/usr/include/qt5/QtWidgets 
-I/usr/include/qt5/QtGui \
     -o qt5-demo qt5-demo.cpp -lQt5Widgets -lQt5Core

And then running ./qt5-demo gives:

     QObject::connect: signal not found in QPushButton
     QObject::connect: signal not found in QWidget
     QObject::connect: signal not found in QWidget
     QXcbConnection: XCB error: 145 (Unknown), sequence: 162, resource 
id: 0, major
     code: 140 (Unknown), minor code: 20
     Bad system call (core dumped)

The demo runs fine in Fedora 21. It also runs in Cygwin when compiled 
with Qt4:

     g++ -I/usr/include/qt4 -I/usr/include/qt4/QtGui -o qt5-demo 
qt5-demo.cpp \
     -lQtGui -lQtCore

And now running the (incorrectly-named!) ./qt5-demo launches the 

Please could you advise what I'm doing wrong.

Many thanks in advance,


[-- Attachment #2: qt5-demo.cpp --]
[-- Type: text/plain, Size: 273 bytes --]

#include <QApplication>
#include <QPushButton>

int main(int argc, char** argv)
  QApplication app(argc, argv);
  QPushButton *button = new QPushButton("Hello!");
  QObject::connect(button, SIGNAL(clicked()), &app, SLOT(quit()));
  return app.exec();

[-- Attachment #3: Type: text/plain, Size: 223 bytes --]

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             reply	other threads:[~2015-02-04 23:20 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-02-04 23:20 David Stacey [this message]
2015-02-05  1:40 ` Jon TURNEY
2015-02-06 14:57   ` David Stacey
2015-02-13 18:32   ` Jon TURNEY
2015-03-02 23:34     ` Yaakov Selkowitz
2015-03-03  9:04       ` Corinna Vinschen
2015-03-03 14:49         ` Jon TURNEY
2015-03-03 17:11           ` Corinna Vinschen

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