In the official example of Garfield++, I can not initialize a pointer of TTree.There will be an error in the making process.
But other parts like TCanvas 、TROOT 、TApplication of ROOT can work well.
Undefined symbols for architecture x86_64: "TTree::TTree(char const*, char const*, int, TDirectory*)", referenced from: _main in mdt.C.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: *** [mdt] Error 1
Above is the output message in my MacOS. In fact, I also tested it in Ubuntu 18, almost the same problem happened.