2.7.3 version of libxml2 includes ATTRIBUTE_PRINTF which is used by wxGTK generating a naming conflict when both libraries are used (see bug #264176). Upstream has released a fix in SVN (see http://mail.gnome.org/archives/xml/2009-April/msg00021.html) but would be great to have the patch in portage as soon as posible to be able to compile again apps suffering this problem. I picked up the diff from SVN and remove references to win32. It applies on 2.7.3 current portage version and tests pass just fine. -r1 ebuild can be found at http://dev.gentoo.org/~yoswink/tmp/libxml2-2.7.3-r1.ebuild
Created attachment 188798 [details, diff] printf macro renaming
in tree with 2.7.3-r1. Thanks for reporting and providing a patch.
*** Bug 280974 has been marked as a duplicate of this bug. ***