c++ - (Qt 5.4.1) This application failed to start because it could not find or load the Qt platform plugin "xcb"

Question

I reinstalled my ubuntu 14.04 and Qt 5.4.1 and Qtcreator.

Qt 5.4.1 was built from source with "-opensource -nomake-test -nomake-example" configure options.

When I open an old project in QtCreator and build it everything's OK.

But when I run this project it shows:

This application failed to start because it could not find or load the Qt platform plugin "xcb".

Available platform plugins are: linuxfb, minimal, offscreen, xcb.

Reinstalling the application may fix this problem. Aborted (core dumped)

So I googled this problem and tried everything. I installed every packages (libxcb series) but nothing can help!

Somebody help me please...

I tried your methods.

When I run ldd command in platform directory, It shows:

You can see that nothing is missing. And actually I have made a softlink in the platform directory called libqxcb.so. There was no libqxcb.so in my platform directory before.

And when I run ldd command to my executable. it shows:

And you can see the error when I execute this file.

Answer 1

For a similar issue, in my case I solved with:

export QT_PLUGIN_PATH=<qt base path>/plugins