buildkernel with INVARIANTS, WITNESS, DEBUG_LOCKS, etc. fails

[Kris Kennaway]

Brian O'Shea wrote:
> Thank you for your reply, Kris.
> 
> --- Kris Kennaway <kris at FreeBSD.org> wrote:
>> Brian O'Shea wrote:
>>> Hello FreeBSD developers,
>>>
>>> Building a FreeBSD 6.2-RELEASE kernel on an Intel Pentium 4 with the
>>> following config options causes buildkernel to fail with undefined
>>> references to stack_save, stack_zero, and stack_print functions:
>>>
>>> makeoptions DEBUG=-g
> 
> options     KDB
> options     DDB
> 
>>> options     INVARIANTS
>>> options     INVARIANT_SUPPORT
>>> options     WITNESS
>>> options     DEBUG_LOCKS
>>> options     DEBUG_VFS_LOCKS
>>> options     DIAGNOSTIC
>>>
> ...
> 
>> I think you also need DDB.
> 
> I added the KDB and DDB options and now the buildkernel succeeds.  Now
> hopefully I can get a crash dump and (try to) start debuging my problem.
> 
>> This is a minor bug which you could send-pr about if you like.
> 
> Would this be a docs bug, or a config bug?

Mostly a docs bug.  In 6.x the stack_save foo isn't really useful 
without DDB.

Kris