>> Think, make must ignore mk.conf or just force -B for backwards
quoted text
>> compatiblity while building src tree.
>
> where in the documentation, besides make(1), is 'make -j' ever talked about?
> and did you see make(1) mentions '-j' in it's BUGS section?

You are totally right. I did not read documentation carefully, and was confused.
Sorry for bothering list.