I don't know how long this message has been appearing. I just noticed
it today with the current 2.5 tree.
I did a make -j3 bzImage. Make version is 3.79.1.
Here is a snippet from the log:
CC net/xfrm/xfrm_output.o
LD net/xfrm/built-in.o
LD net/built-in.o
GEN .version
make[1]: warning: jobserver unavailable: using -j1. Add `+' to parent make rule.
CHK include/linux/compile.h
UPD include/linux/compile.h
CC init/version.o
LD init/built-in.o
LD vmlinux
Steven