Dear people,
I ran into the same issue again today, and I seemed to have solved it by running
brew install llvm@14
and then I added it to my path with
echo 'export PATH="/usr/local/opt/llvm@14/bin:$PATH"' >> ~/.zshrc
EDIT: I actually had to remove the line from my zshrc because it then caused an issue when building ROOT.
Hope it helps,
Sarah