[ Took out the following to make leaner kernel ]

> #options        KTRACE              # system call tracing support
> #options    DDB 
> 
> #options    DIAGNOSTIC  
> #options    SCSIDEBUG   

In general, these options control #ifdefs in the code.  The best way to compile
at this point is to make clean; make, but only if you have a couple of hours
to spare...

Another way, of course, is to

find . -type f -print|xargs grep -l DDB

and remove the corresponding binaries (if I knew enough sed to compute the
basename, I'd continue the script to automatically delete them... :-)

> when i booted the new kernel, i got something like:
> MNT RPC failed

Never seen this one before.  Are you booting from disk or net?

> i did a config TUATARA, then cd'd to compile/... and did make depend ; make.

Yup.  It's very much like compiling babybop's kernel.

> is it possible that i complete kernel build would not have caused the
> above error?

Possible.  BTW, the options you removed are not really pigs.  I'd leave
them in, esp. DDB.  If the system kacks, DDB can be useful in reporting the
problem or investigating.