I got the same error on a Linux system. However, `wx-config --cflags` was already defined when the project was setup. Looking at the code where the error was flagged, there were a number of options including the following:
!defined(__WXMOTIF__) && \ !defined(__WXMSW__) && \ !defined(__WXPALMOS__)&& \ !defined(__WXGTK__) && \
By adding __WXGTK__ (I assume that is the default) to the compiler settings defines, I got this error to go away. Also, once this was done, several libraries had to be added in the linker settings. These were:
libwx_baseu-2.8.so and libwx_gtk2u_aui-2.8.so
I had expected that `wx-config --libs` would handle this automatically, but apparently it just sets the directories.