MacOS Sierra 10.12
MacOS High Sierra 10.13.6

In file included from ~/boost/boost/process.hpp:24:
In file included from ~/boost/boost/process/async_system.hpp:22:
In file included from ~/boost/boost/process/child.hpp:21:
In file included from ~/boost/boost/process/detail/child_decl.hpp:30:
/boost/boost/process/detail/posix/wait_for_exit.hpp:60:7: error: expected unqualified-id
::sigemptyset(&sigset);
^
/usr/include/signal.h:125:26: note: expanded from macro 'sigemptyset'
#define sigemptyset(set) (*(set) = 0, 0)
^
What am I doing wrong? Any ideas? Thanks in advance.

and few same errors....

PS: I am using boost 1.68.0 built from sources.