Bootstrapping from stable/9 to head?

[NGie Cooper]

Hi Ian and Warner,
	I realize this isn’t a path that’s currently supported, but when I was running a test for jhb on stable/9 (ref9-amd64.freebsd.org to be exact), I ran into this error:

bmake[1]: "/scratch/tmp/ngie/svn/Makefile" line 466: "Target architecture for arm/conf/A20 unknown.  config(8) likely too old."
*** [universe_arm_kernels] Error code 1

bmake: stopped in /scratch/tmp/ngie/svn

	I was wondering if there was a way where someone could more reliably bootstrap from stable/9 to stable/10, or if the directions just need to be changed to “upgrade to the latest release of 10, then upgrade to 11-CURRENT”?
	Also, config is a build tool in Makefile.inc1… I was wondering if the check in Makefile is a bit too stringent / incorrect.
Thanks,
-NGie