Feels like a bug in the wxWidgets 2.8 branch:
I have Xinerama installed, but the default install path for the .so on *Ubuntu is /usr/lib/x86_64-linux-gnu/.
Debugging the configure script showed, that the search paths for libs are:
/usr/local/lib
/usr/local/X11/lib
/usr/local/lib/X11
/usr/local/X11R6/lib
/usr/local/lib/X11R6
/usr/Motif-2.1/lib
/usr/Motif-1.2/lib
/usr/lib/Motif1.2
/usr/dt/lib
/usr/openwin/lib
/usr/lib/Xm
/usr/X11R6/lib
/usr/X11R6.4/lib
/usr/lib/X11R6
/usr/X11/lib
/usr/lib/X11
/usr/XFree86/lib/X11
/usr/pkg/lib
/usr/local/X1R5/lib
/usr/local/lib/X11R5
/usr/X11R5/lib
/usr/lib/X11R5
/usr/local/X11R4/lib
/usr/local/lib/X11R4
/usr/X11R4/lib
/usr/lib/X11R4
/usr/openwin/share/lib
/usr/lib
Basically everywhere BUT the right location. I don't think my shell-script-fu is strong enough to untangle the mess of $SEARCH_LIB.
Also looking at wx3.0+ configure shows that it no longer checks for Xinerama