clang++ by hand

% clang++ -stdlib=libc++ -pthread -std=c++17 -m64 -I/opt/homebrew/Cellar/root/6.32.08/include/root hsimple.C -o hsimple -L/opt/homebrew/Cellar/root/6.32.08/lib/root -lCore -lImt -lRIO -lNet -lHist -lGraf -lGraf3d -lGpad -lROOTVecOps -lTree -lTreePlayer -lRint -lPostscript -lMatrix -lPhysics -lMathCore -lThread -lMultiProc -lROOTDataFrame -Wl,-rpath,/opt/homebrew/Cellar/root/6.32.08/lib/root -stdlib=libc++ -lpthread -lm -ldl
Undefined symbols for architecture arm64:
  "_main", referenced from:
      <initial-undefines>
ld: symbol(s) not found for architecture arm64
clang: error: linker command failed with exit code 1 (use -v to see invocation)