Qt4 and Kubuntu coexisting?

[drhex]

I have recently installed kubuntu 8.10, which uses Qt4, and after that downloaded and did make + make install of the latest Qt sources.

when I try from a command prompt to run i.e. gwenview i get:

gwenview: symbol lookup error: /usr/lib/libQtDBus.so.4: undefined symbol: _ZN14QObjectPrivate15checkWindowRoleEv

gwenview: symbol lookup error: /usr/lib/libQtDBus.so.4: undefined symbol: _ZN14QObjectPrivate15checkWindowRoleEv

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A web search indicated that the problem is probably due to conflicts between Kubuntu's Qt4 and the Qt4 I compiled.

Any hint on how to make them coexist peacefully?

[jpn]

Where did you install the manually compiled Qt?

[drhex]

I did not specify a location to ./configure, so it would be the default

/usr/local/Trolltech/Qt-4.5.0-tp1

Did some more research which led me to this:

>ldd `which gwenview` | grep Troll
libQtCore.so.4 => /usr/local/Trolltech/Qt-4.5.0-tp1/lib/libQtCore.so.4 (0xb74d2000)
libQtGui.so.4 => /usr/local/Trolltech/Qt-4.5.0-tp1/lib/libQtGui.so.4 (0xb6911000)
libQtXml.so.4 => /usr/local/Trolltech/Qt-4.5.0-tp1/lib/libQtXml.so.4 (0xb6489000)
libQtSvg.so.4 => /usr/local/Trolltech/Qt-4.5.0-tp1/lib/libQtSvg.so.4 (0xb6345000)
libQtNetwork.so.4 => /usr/local/Trolltech/Qt-4.5.0-tp1/lib/libQtNetwork.so.4 (0xb6243000)

>ldd `which gwenview` | grep Troll
libQtCore.so.4 => /usr/local/Trolltech/Qt-4.5.0-tp1/lib/libQtCore.so.4 (0xb74d2000)
libQtGui.so.4 => /usr/local/Trolltech/Qt-4.5.0-tp1/lib/libQtGui.so.4 (0xb6911000)
libQtXml.so.4 => /usr/local/Trolltech/Qt-4.5.0-tp1/lib/libQtXml.so.4 (0xb6489000)
libQtSvg.so.4 => /usr/local/Trolltech/Qt-4.5.0-tp1/lib/libQtSvg.so.4 (0xb6345000)
libQtNetwork.so.4 => /usr/local/Trolltech/Qt-4.5.0-tp1/lib/libQtNetwork.so.4 (0xb6243000)

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>env | grep LIBRARY
LD_LIBRARY_PATH=/usr/local/Trolltech/Qt-4.5.0-tp1/lib:/usr/local/lib

>env | grep LIBRARY
LD_LIBRARY_PATH=/usr/local/Trolltech/Qt-4.5.0-tp1/lib:/usr/local/lib

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I tried switching the order of the two paths in LD_LIBRARY_PATH, and then gwenview starts without complaints.. but.. I am also developing Qt apps and I want them to use the manually installed Qt lib. Hmm. I suppose I could either start them like this

>LD_LIBRARY_PATH=/usr/local/Trolltech/Qt-4.5.0-tp1/lib:/usr/local/lib myapp

>LD_LIBRARY_PATH=/usr/local/Trolltech/Qt-4.5.0-tp1/lib:/usr/local/lib myapp

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or figure out how to statically link everything into the binary. Is that how you gurus would keep two versions of Qt4 separate?

[wysota]

Remove /usr/local/Trolltech/Qt-4.5.0-tp1/lib from the environment variable, you probably don't need it there.

[drhex]

Amazingly, that worked (although I don't understand why). I changed the initial setup of LD_LIBRARY_PATH and logged out+in again to ensure that no traces of previous settings were left.

ldd on my application still refers to the shiny new 4.5.0-tp1 for libQtGui and libQtCore even after a full recompile, while ldd on the system's standard applications only refer to its own libraries.

Perfect!