The Makefile in /path/to/boxes-1.0.1/src/regexp uses cflag "-traditional" which is deprecated for current compiler versions. Without it, the programm compiles successfully also on newer gcc releases.
Created attachment 87244 [details, diff] Patch for the "/path/to/boxes-1.0.1/src/regexp/Makefile" Makefile, which removes "-traditional" cflags. Patches one of boxes Makefile to enale successfull compilation even on newer gcc versions.
Please apply patch to tree.
this has been in boxes-1.0.1-gentoo.diff since it was first added in 2001. http://sources.gentoo.org/viewcvs.py/gentoo-x86/app-misc/boxes/files/boxes-1.0.1-gentoo.diff?view=markup