I am going to install sparsehash-2.0.4 into Mac OS 10.15.7. Setting of C++ is not so easy in my PC.
$./configure CXX=“gcc" #worked, but I cannot make with the following commands.
$ CXX="gcc" make
$ CXX="g++" make
$ CC="gcc" make and so on.

The error is like below.

(std::__1::basic_ostream<char, std::__1::char_traits >&, char const*, unsigned long) in template_util_unittest.o
std::__1::ostreambuf_iterator<char, std::__1::char_traits > std::__1::__pad_and_output<char, std::__1::char_traits >(std::__1::ostreambuf_iterator<char, std::__1::char_traits >, char const*, char const*, char const*, std::__1::ios_base&, char) in template_util_unittest.o
Dwarf Exception Unwind Info (__eh_frame) in template_util_unittest.o
ld: symbol(s) not found for architecture x86_64
clang: error: linker command failed with exit code 1 (use -v to see invocation)
make[1]: *** [template_util_unittest] Error 1
make: *** [all] Error 2

I assume this will be the problem of Mac, rather than the package, but any advices or suggestions will greatly help me. Thank you in advance.