11%] Building CXX object miner/pow/CMakeFiles/pow.dir/impl/crypto/equihash_impl.cpp.o
/Users/alexr/Code/beam/miner/pow/impl/crypto/equihash_impl.cpp:26:10: fatal error: 'optional' file not found
seems latest clang version doesn't support C++17 on Travis
so, I used gcc7 to build Beam on macosx
use brew install gcc@7 command to install it and export CXX=g++-7 before run cmake
11%] Building CXX object miner/pow/CMakeFiles/pow.dir/impl/crypto/equihash_impl.cpp.o /Users/alexr/Code/beam/miner/pow/impl/crypto/equihash_impl.cpp:26:10: fatal error: 'optional' file not found
include
1 error generated. make[2]: [miner/pow/CMakeFiles/pow.dir/impl/crypto/equihash_impl.cpp.o] Error 1 make[1]: [miner/pow/CMakeFiles/pow.dir/all] Error 2 make: *** [all] Error 2