In order to build cadabra on osx, first install XCode and then make
sure that a working homebrew installation is present,

  http://brew.sh

You need to install several packages from homebrew in order to build
modglue and cadabra. Install them with

 brew install pkgconfig libsigc++ libtool pcre pcre++ gmp 
 brew tap NickBeeuwsaert/homebrew-native
 brew install gtkmm-native

The last two lines instruct brew to get a native OS X version of the
GTK libraries, instead of a version that uses X11 and requires
XQuartz. You can build with the X11 versions as well (i.e. you can
instead do 'brew install gtkmm'), but cadabra will not look as nice.

Install modglue with

   cd modglue
   ./configure
   make
   sudo make install

Then install cadabra with

   cd cadabra
   export CXXFLAGS=-I/usr/local/include
   ./configure --enable-runtime-dependency-check
   
