note ("test of warnings emitted"); { local $Range::Validator::WARNINGS; my ($stdout, $stderr, @result) = capture { Range::Validator::validate() }; unlike($stderr, qr/^Empty list passed in/, "no warning for empty list unless \$Range::Validator::WARNINGS"); $Range::Validator::WARNINGS = 1; ($stdout, $stderr, @result) = capture { Range::Validator::validate() }; like( $stderr, qr/^Empty list passed in/, "right warning for empty list if \$Range::Validator::WARNINGS"); }