../kernel/bpf/stackmap.c: In function ‘__bpf_get_stack’:
../kernel/bpf/stackmap.c:480:33: error: ‘num_elem’ undeclared (first use in this function)
  480 |         trace_nr = (trace_nr <= num_elem) ? trace_nr : num_elem;
      |                                 ^~~~~~~~
../kernel/bpf/stackmap.c:480:33: note: each undeclared identifier is reported only once for each function it appears in
make[5]: *** [../scripts/Makefile.build:287: kernel/bpf/stackmap.o] Error 1
make[4]: *** [../scripts/Makefile.build:556: kernel/bpf] Error 2
make[3]: *** [../scripts/Makefile.build:556: kernel] Error 2
make[3]: *** Waiting for unfinished jobs....
make[2]: *** [/home/nipa/bpf-next/wt-0/Makefile:2011: .] Error 2
make[1]: *** [/home/nipa/bpf-next/wt-0/Makefile:248: __sub-make] Error 2
make: *** [Makefile:248: __sub-make] Error 2