is that how you did it? ./configure && make? even if that had worked, you wouldn't be able to compile kde. see the instalation manual for the correct configure args to ./configure.
however, i also tried to build qt on my own and i failed miserably, but that came from wrong prefix arg and so i always got errors compiling kde. then i used the binpackage (slackware) and i found out that's the better way, because make install will not give you everything you need. it gives you libraries but there is whole lot more to qt. qmake for example will not be installed by make install
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