
perl Makefile.PL [--use_defaults=<1|0>] [-u=<1|0>] -u=1 or --use_defaults=1: Use default values, do not ask for values. This option is only available if you have Getopt::Mixed installed.

Converts variables, like so:
$a = '~_~SUPPORT_FILES_DIR~_~';
into
$a = '/blah/blah/';