Building Qt as a static

gmahan

I am trying to build Qt, on my Fedora 21 x64, as a static libraries so I can build my application to link against the static libraries. I have followed the instructions on this blog :https://wiki.qt.io/Building_Qt_5_from_Git, and have successfully compiled the qt source libraries. I tried to build an application from the examples directory and everything compiled fine. But I get the following error when trying to run the application:

This application failed to start because it could not find or load the Qt platform plugin "xcb".
Reinstalling the application may fix this problem.

I have already installed the xcb-util package.

#yum install xcb-util
Loaded plugins: langpacks
Package xcb-util-0.4.0-2.fc21.x86_64 already installed and latest version
Nothing to do

[gmahan@localhost platforms]$ pwd
/home/gmahan/qt5/qtbase/plugins/platforms
[gmahan@localhost platforms]$ ls
libqlinuxfb.a libqminimal.a libqoffscreen.a libqxcb.a libqlinuxfb.prl libqminimal.prl libqoffscreen.prl libqxcb.prl

I'm not sure how to proceed. I haven't found how to resolve this after reading a few similar problems.

SGaist

Hi,

Static plugins need special handling, see Q_IMPORT_PLUGIN for more information.

gmahan

@SGaist Thanks for pointing this out.

After reading a bit I added the following to the .pro and the main.cpp file.

TEMPLATE = app
LIBS += /home/gmahan/qt5/qtbase/plugins/platforms/libqxcb.a

In main.cpp, I added the following:

 #include <QApplication>
 #include <QtPlugin>
 #include "mapzoom.h"

 Q_IMPORT_PLUGIN(qxcb)

Gave me the following error in make:

/home/gmahan/qt5/qtbase/examples/embedded/lightmaps/main.cpp:46: undefined reference to `qt_static_plugin_qxcb()

But according to http://doc.qt.io/qt-5/plugins-howto.html#static-plugins, all I need is

QTPLUGIN += qxcb

The above line gave me the following warning :

Project WARNING: Redundant entries in QTPLUGIN: qxcb

SGaist

Aren't you missing a -l in your LIBS line ?

gmahan

@SGaist Didn't think that was necessary for static libraries, works in my other project without the -L for static libs, but I'll try it nevertheless.

SGaist

not -L -l. -L is to add entries to the folder list the linker will search into