Before attempting autoconfiguration the directory tree has to be set to the clean state. This is done with the following command :
make distclean
This command deletes any existing object files, executables produced by build process, config.cache, Makefiles produced by previous run of configure script.
Before running configure one may wish to review (and probably manually edit) files makeisdc1.in and Makefile.in. makeisdc1 and Makefile should not be edited since their contents will be overwritten by subsequent run of $ISDC_ENV/bin/ac_stuff/configure script.
To autoconfigure PIL library one has to run :
$ISDC_ENV/bin/ac_stuff/configure
$ISDC_ENV/bin/ac_stuff/configure script adapts Makefile to C and F90 compilers tastes. If there is no F90 compiler available configure script disables compilation of F90 source files. If configure script is unable to automatically find correct C and F90 compiler one can set CC, F90, CFLAGS and F90FLAGS environment variables to force configure script to choose specific compilers/options. For example configure script tends to favor gcc over other C compilers. So if you have gcc and other C compiler it will always choose gcc. If you want to use C compiler other then gcc please type :
setenv CC name_of_your_C_compiler (cc is quite common)
before running ./configure