I tried to reopen bug #11858 with the following additional comment: I got a similar failure in kdelibs-3.1.3. After researching buzilla, I found this bug, so I have reopened it. I believe the problem in my case is that /usr/X11R6/lib/libz.a was created when I recently emerged net-print/xprint. Therefore, I believe the corrections to the xfree ebuild described in additional comment #3 above should also be applied to the xprint ebuild. Please refer to bug #11858.
there were a lot of other files overwritten too, cleaned it all up :)