The recommended package manager is Homebrew. To install dependencies, use:
brew install autoconf automake libtool flex bison boost eigen
Once these dependencies are installed, follow the usual instructions to install Birch itself.
Birch requires a newer version of Bison than that provided by macOS. The above command installs an appropriate version. If, however, you get a syntax error in
parser.ypp when trying to install the Birch compiler, it is likely that the system version is still being used. In that case, try:
brew link --force bison