xcode5.txt

% brew uninstall bison
% brew update
% brew versions bison
  3.0      git checkout b744b43 /usr/local/Library/Formula/bison.rb
  2.7.1    git checkout 804bcf6 /usr/local/Library/Formula/bison.rb
  2.7      git checkout adf87c6 /usr/local/Library/Formula/bison.rb
% cd /usr/local
% git checkout 804bcf6 Library/Formula/bison.rb
% brew install bison

# Then make sure /usr/local/opt/bison/bin is early in your PATH when
# you configure and build PHP to use the newer bison