View Full Version : Multiple Versions of Qt

20th April 2012, 16:52
This is a Qt/Linux question. I'm not sure what section it's supposed to go into and I apologize if it's in the wrong place.

I need to hack my qt library a bit, and I have it compiled and sitting in my /usr/local/Trolltech/Qt-4-8-0.

At the same time I'm running Kubuntu which runs on Qt-4.8-1. When I run my app I get:
Cannot mix incompatible Qt library (version 0x40801) with this library (version 0x40800)

So I tried setting LD_LIBRARAY_PATH=/usr/local/Trolltech/Qt-4-8-0/lib:$LD_LIBRARAY_PATH

no cigar

I tried doing lld MyApp after exporting the above LD_LIBRAR_PATH and it's not pointing to any qt-4.8.1 anywhere.

Can anyone point me in the right direction with this?

Thank you.

22nd April 2012, 01:37
Sounds to me like the Qt DLLs are already loaded by Kubuntu, so rather than trying to load its own DLLs, your app tries to use the ones already there and fails. I don't know how in linux you force an app to use a defined set of DLLs; in the Windows world, M$ invented the "side-by-side" system and the use of manifests to circumvent this DLL hell.


And shouldn't this be LD_LIBRARY_PATH instead of your incorrectly spelled version? Maybe that is the whole source of your problem.