README.Macintosh

Building n on macOS-X requires :

   1) XCode - available through the App Store
       NB you will also need the commandline tools for XCode

              xcode-select --install

   2) There are various 3rd party libraries required - fortunately someone else has done the
      hard work of porting them.  There are several options, we have only looked at
      MacPorts and Homebrew which seem to be amongst the most popular.  If you don't
      already have a collection, look at :

          Homebrew : http://brew.sh/

   3) If you want to use gfortran, make sure you have at least version 8.2.

             brew install gcc

   4) You will need netcdf - this is available from Homebrew :

             brew install netcdf

   5) To build the GUI you will need libgd - this is available through Homebrew

             brew install gd

   6) To build a version including FABM you will need cmake, both brew and port seem to include it
      in their compiler bundles, but in case they don't :

             brew install cmake

Note:
   cmake attempts to verify that compiles actually work, unfortunately it
   attempts to build an executable test program by linking to libgcc_s.dylib.
   This file doesn't exist on the mac, normally it would be a link to libgcc_s.1.dylib.
   My workaround for this is to add a symlink in the fortran library directory :

     cd /opt/intel/lib
     sudo ln -s /usr/lib/libgcc_s.1.dylib libgcc_s.dylib

Note:
    GLM source includes a script - "macpkg.sh" to include non-standard libraries
    into the glm.app binary.

Note:
   GLM requires gfortran v8 or later in order to build correctly - previous versions of gfortran
   had a bug in the C compatibility that prevented correct compilation.

Note:
   If you have upgraded Xcode you might need to make it use the right version :
      sudo xcode-select -s /Applications/Xcode.app/Contents/Developer
   and you may need to upgrade the commandLine tools too :
      sudo xcode-select --install