[2.5-bk] make[1]: warning: jobserver unavailable: using -j1. Add

[Steven Cole]

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