> I have compiled qextserialport and saved a link to the generated library > file (libqextserialport.so.1.0.0) in /usr/lib/. I suggest to create another symbolic link "/usr/lib/libqextserialport.so" pointing to the lib, then run ldconfig to update the linker cache. See the content of /usr/lib/ for how it should look like. HTH, Martin