Bootstrap Emacs with MinGW under WindowsXP failed due to compiling
lisp/usr/vc-dav.el requires file DOC must be present under directory etc/

And I find this problem has been reported before, and a patch has been
proposed:

http://lists.gnu.org/archive/html/emacs-pretest-bug/2005-05/msg00388.html

It seems nobody care about that.