gcc dependencies issue when installing DNest4 in macOS Monterey

[jlillo]

While trying to install the package in my macOS Monterey (12.0.1) I the the following issue related to the gcc dependencies:

g++ -std=c++11 -O3 -march=native -Wall -Wextra -pedantic -DNDEBUG -c -o Barrier.o Barrier.cpp
In file included from /opt/local/include/gcc49/c++/bits/postypes.h:40:0,
from /opt/local/include/gcc49/c++/bits/char_traits.h:40,
from /opt/local/include/gcc49/c++/string:40,
from /opt/local/include/gcc49/c++/stdexcept:39,
from /opt/local/include/gcc49/c++/array:38,
from /opt/local/include/gcc49/c++/tuple:39,
from /opt/local/include/gcc49/c++/mutex:38,
from Barrier.h:4,
from Barrier.cpp:1:
/opt/local/include/gcc49/c++/cwchar:44:19: fatal error: wchar.h: No such file or directory
#include <wchar.h>
^
compilation terminated.
make: *** [Barrier.o] Error 1

Any idea what could be going wrong?
Thanks a lot,
Jorge