use constant RUNNING_ON_WINDOWS => ($^O =~ /^(?:mswin|dos|os2)/oi);
use POSIX qw(:sys_wait_h WIFEXITED WIFSIGNALED WIFSTOPPED WEXITSTATUS WTERMSIG WSTOPSIG
:signal_h SIGINT SIGTERM SIGKILL SIGABRT SIGSEGV);
use constant RUNNING_ON_WINDOWS => ($^O =~ /^(?:mswin|dos|os2)/oi);
use POSIX qw(:sys_wait_h WIFEXITED WIFSIGNALED WIFSTOPPED WEXITSTATUS WTERMSIG WSTOPSIG
:signal_h SIGINT SIGTERM SIGKILL SIGABRT SIGSEGV);
'debug|d' => \$opt{"debug"},
'difftool=s' => \$diff_tool,
'debug|d' => \$opt{"debug"},
'difftool=s' => \$diff_tool,