Installing #wxwidgets 3.0.x under #gentoo , default is 2.8

If you install wxwidgets with emerge wxGTK on gentoo default is 2.8

emerge -p =x11-libs/wxGTK-3.0.2.0

add /etc/portage/package.accept_keywords

# required by =x11-libs/wxGTK-3.0.2.0 (argument)
=x11-libs/wxGTK-3.0.1.1 ~amd64

emerge -1 =x11-libs/wxGTK-3.0.2.0

# eselect wxwidgets list                                                                                                             

Available wxWidgets profiles:

  [1]   gtk2-unicode-3.0 *

  [2]   gtk2-unicode-release-2.8

# eselect wxwidgets set 1

then continue with flamerobin compiling from source 

./configure

make install