flame@yamato advancemenu-2.4.13 % find . | grep expat ./advance/expat ./advance/expat/expat-1.95.8.diff ./advance/expat/README ./advance/expat/COPYING ./advance/expat/xmltok_impl.h ./advance/expat/xmltok.h ./advance/expat/xmlrole.h ./advance/expat/utf8tab.h ./advance/expat/nametab.h ./advance/expat/latin1tab.h ./advance/expat/internal.h ./advance/expat/iasciitab.h ./advance/expat/expatcfg.h ./advance/expat/expat_external.h ./advance/expat/expat.h ./advance/expat/asciitab.h ./advance/expat/ascii.h ./advance/expat/xmltok_ns.c ./advance/expat/xmltok_impl.c ./advance/expat/xmltok.c ./advance/expat/xmlrole.c ./advance/expat/xmlparse.c
I checked the ebuilds; since --disable-expat uses the _internal_ copy of libexpat, the trick is just to drop the expat USE flag, always depend on it, and always pass --enable-expat. Both packages seems not to be able to avoid using expat, so we should use the system copy rather than the internal copy in any case.
Fixed, thanks.