It may be useful to be able to build a modified extensible SDK from within the extensible SDK itself, to allow you to add additional software and then redistribute the resulting SDK easily.
Implementation merged to master: http://git.yoctoproject.org/cgit/cgit.cgi/poky/commit/?id=41eb36dc4ce7feece2f63c7cae80478f5376459e http://git.yoctoproject.org/cgit/cgit.cgi/poky/commit/?id=25d9c4e02a90b1fd8c6a2036d29fd2cf87eca098