make run/demo on a linux base on a 64 bit centos distro - SYS_waitpid not declared

[J T]

$ make run/demo
...
  Program core/core
    COMPILE  cpu_session_extension.o
In file included from
/home/xx/source/genode/base-linux/src/core/cpu_session_extension.cc:11:0:
/home/xx/source/genode/base-linux/src/core/include/core_linux_syscalls.h:
In function ‘int lx_pollpid()’:
/home/xx/source/genode/base-linux/src/core/include/core_linux_syscalls.h:115:20:
error: ‘SYS_waitpid’ was not declared in this scope
make[2]: *** [cpu_session_extension.o] Error 1
make[1]: *** [core.prg] Error 2
make: *** [gen_deps_and_build_targets] Error 2

Prior to this I had to run tool/toolchain since the other method for
using genode's custom precompiled toolchain didnt work for me.