SYNOPSIS

use Module::Build;
use Devel::AssertC99; # <== check at here
my $builder = Module::Build->new(
configure_requires => {
'Devel::AssertC99',
},
...
);
$builder->create_build_script;

DESCRIPTION

This module checks C99 compiler's availability. If it's not available, exit with code 0.

It makes CPAN testers status as N/A.