[csw-maintainers] make -j60 package, parallel build possible? build8s 96% idle while building ...

[THURNER rupert]

as "top" said "96% idle" on build8s, i thought i'd try:
   make -j60 package

but .. it gives:
   gmake[1]: warning: jobserver unavailable: using -j1.  Add `+' to
parent make rule.

is there a possibility to trigger parallel compiles?

rupert.