[gentoo-user] Compile kde-apps/libkdcraw-4.14.3 error

[Wallance Lee]

Hi, everyone
I want to install media-gfx/digikam for picture manager.And it depends on 
kde-apps/libkdcraw-4.14.3.But it compiled error like this
/usr/include/libraw/libraw_datastream.h:154:17: error: exception handling 
disabled, use -fexceptions to enable
           throw LIBRAW_EXCEPTION_IO_EOF;
I use gcc-4.9.3 and kde plasma 5.
What should I do to avoid this error?
Thank you