Ok, installed mysql 5.7 and it went well until this:
Ld build/src/server/authserver/Release/authserver normal x86_64
cd /Users/synapse/Downloads/Trinity/TrinityCore
export MACOSX_DEPLOYMENT_TARGET=10.13
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/clang++ -arch x86_64 -isysroot /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.13.sdk -L/Users/synapse/Downloads/Trinity/TrinityCore/build/src/server/authserver/Release -F/Users/synapse/Downloads/Trinity/TrinityCore/build/src/server/authserver/Release -filelist /Users/synapse/Downloads/Trinity/TrinityCore/build/src/server/authserver/TrinityCore.build/Release/authserver.build/Objects-normal/x86_64/authserver.LinkFileList -mmacosx-version-min=10.13 -Wl,-search_paths_first -Wl,-headerpad_max_install_names /Users/synapse/Downloads/Trinity/TrinityCore/build/src/server/shared/Release/libshared.a /Users/synapse/Downloads/Trinity/TrinityCore/build/src/server/database/Release/libdatabase.a /Users/synapse/Downloads/Trinity/TrinityCore/build/src/common/Release/libcommon.a /usr/local/lib/libboost_system-mt.dylib /usr/local/lib/libboost_filesystem-mt.dylib /usr/local/lib/libboost_thread-mt.dylib /usr/local/lib/libboost_program_options-mt.dylib /usr/local/lib/libboost_iostreams-mt.dylib /usr/local/lib/libboost_regex-mt.dylib /Users/synapse/Downloads/Trinity/TrinityCore/build/dep/fmt/Release/libfmt.a /Users/synapse/Downloads/Trinity/TrinityCore/build/dep/g3dlite/Release/libg3dlib.a /Users/synapse/Downloads/Trinity/TrinityCore/build/dep/recastnavigation/Detour/Release/libDetour.a /usr/lib/libz.dylib /usr/local/opt/openssl/lib/libssl.dylib /usr/local/opt/openssl/lib/libcrypto.dylib /usr/local/mysql/lib/libmysqlclient_r.dylib -Xlinker -dependency_info -Xlinker /Users/synapse/Downloads/Trinity/TrinityCore/build/src/server/authserver/TrinityCore.build/Release/authserver.build/Objects-normal/x86_64/authserver_dependency_info.dat -o /Users/synapse/Downloads/Trinity/TrinityCore/build/src/server/authserver/Release/authserver
clang: error: no such file or directory: '/usr/local/mysql/lib/libmysqlclient_r.dylib'
** BUILD FAILED **
The following build commands failed:
Ld build/src/server/authserver/Release/authserver normal x86_64
(1 failure)