is building kernel in /sys/amd64/conf depreciated in 11 ?

Hi,

as subject - is building kernel in /sys/amd64/conf depreciated?

I can get a modified kernel to build and install in /usr/src but not
in /sys/amd64/conf. I always used to be able to do this in there, then
again I either used -RELEASE or -STABLE. I used to do it like this:

1. cd /sys/amd64/conf
2. cp GENERIC MYKERNEL
3. [make changes to MYKERNEL and save]
4. config MYKERNEL
5. cd ../compile/MYKERNEL
6. make cleandepend && make depend && make

This fails *every time* during make. It fails at this point:

Make[1]: "/storage/usr/ports/Mk/bsd.port.mk" line 1204: UNAME_r
(11.0-CURRENT) and OSVERSION () do not agree on major version number.
       
*** [all] Error code 1
              
make: stopped in /storage/usr/src/sys/amd64/compile/PUMPKIN                     

The error still happens if I refresh all my sources, build a new world
with a generic kernel and reboot and then try the old method again.

I *can* build a custom kernel if I cd into /usr/src and do

1. make buildkernel KERNCONF=MYKERNEL
2. make installkernel KERNCONF=MYKERNEL

Basically I'm asking is this change of behaviour documented and/or am
I doing it wrong?

thanks,
-- 
John