NOTE: Astro::FITS::CFITSIO v1.09 requires cfitsio library version
      3.31 or later. It can be obtained from
      http://heasarc.gsfc.nasa.gov/fitsio

NOTE: gcc takes a very long time to compile CFITSIO.c (created from
      CFITSIO.xs) with -O2 optimization. With -O0, it takes about one
      tenth the time. This is the explanation for the optimization
      flag below.


1. Makefile.PL needs to know where the cfitsio library is installed.

   If the ExtUtils::PkgConfig Perl module is installed and the
   cfitsio.pc file is installed where pkg-config can find it
   then the library will be automatically discovered.  To test
   the latter condition, run

      pkg-config --libs cfitsio

   If this is not the case or you wish to override the pkg-config
   cfitsio metainformation then set the CFITSIO environment variable
   pointing to the location of your cfitsio library and headers (e.g.,
   /usr/local/cfitsio), or a prefix with include and lib
   subdirectories containing the cfitsio headers and library,
   respectively (e.g., /usr/local).

   $ CFITSIO=/usr/local/cfitsio         # Bourne shell and variants
   $ export CFITSIO

   % setenv CFITSIO /usr/local/cfitsio  # C shell variants

2. perl Makefile.PL OPTIMIZE=-O0

3. make

4. make test

5. If you want, compare the output of the testprog/testprog*.pl
   scripts to cfitsio's testprog.c. There is a small shell script -
   "runtests" - included to make this easier.

6. make install

If compilation fails, please make sure the version of cfitsio you're
using matches that listed in README as a requirement for this version
of the module.

If compilaton succeeds but 'make test' fails due to unresolved
symbols, you should try explicity setting the libcfitsio.a to link
to. In Makefile.PL, add the following key to the WriteMakefile()
argument list:

      'MYEXTLIB' => '/path/to/libcfitsio.a',