a patch to the upgrade guide would be wrong.
The problem is the patching process (a special case of the userland build
process) assumes a clean obj dir. This has nothing to do with upgrades. If
you try to rebuild the same userland utility more than once for /any/
reason without clearing the obj dir, you can run into problems. Clearing
the obj directory as part of the upgrade is like flushing your toilet based
on the date -- may help, but after a while, things start to stink. It isn't
the general (or proper) solution.
ANYTHING left in /usr/obj will be a possible problem.
ANYTHING left ANYWHERE will be a possible problem anytime anything assumes
(or has/likes to assume) that it is working with a clean slate.
"Fixing" minor problems (and bending everything else out of shape)
does NOT make for better systems.
For me, I prefer things (upgrade/update/whatever) that do as little
collateral damage as possible. (And anytime you want/need to find out
what went wrong you do NOT clean up everything first.)
