Installing ISIS on MacOS X

Basic Instructions

1. Make sure your system software is up to date.
   • Repeatedly run Software Update until no new software is available.
   • Download and install the latest Xcode.
2. Install a compatible set of compilers for C, C++ and Fortran (eg. gcc, g++ and gfortran).

   Xcode provides C and C++ compilers (gcc and g++), but it does not provide a Fortran compiler. While a number of sources provide compilers for the Mac, it is sometimes difficult to find a set of compilers that are compatible with each other and that can also compile HEASOFT correctly.

   Most people who use ISIS also wish to use the XSPEC spectral model library from HEASOFT. For that reason, it is usual to choose compilers from among those supported by HEASOFT.

3. Specify compiler environment variables.

   Although 64-bit Macs are now common, XSPEC apparently does not work correctly on MacOS unless compiled in 32-bit mode. When compiling with GNU compilers, use the -m32 compiler option to compile in 32-bit mode.

   To make sure that the -m32 option is used everywhere, it's a good idea to include it in the compiler environment variable definition. Specify C, C++ and Fortran compilers by setting the CC, CXX and FC environment variables:

      setenv CC  "/usr/bin/gcc -m32"         # csh-compatible
      setenv CXX "/usr/bin/g++ -m32"
      setenv FC  "/usr/local/bin/gfortran -m32"
      setenv LDFLAGS "-m32"
   

   or

      export CC="/usr/bin/gcc -m32"          # sh-compatible
      export CXX="/usr/bin/g++ -m32"
      export FC="/usr/local/bin/gfortran -m32"
      export LDFLAGS="-m32"
   

4. Build XSPEC from source, making sure to apply all the current software patches.
5. Follow the usual installation instructions to compile and install ISIS from the source code. It is important to use the same compilers that were used to build XSPEC.

Mac Install FAQ

A1. Depending on how you installed X-windows, the X11 libraries may be in a non-standard location, possibly resulting in an error message saying, e.g. "libX11 not found". One solution is to provide the correct path to your X11 files when you run configure, for example:

    ./configure --with-headas=$HEADAS \
                --x-libraries=/usr/X11/lib \
                --x-includes=/usr/X11/include