void foo()
{
    string command;
    version (Posix)
        command ~= " 2> /dev/null 1> /dev/null";

    version (Posix)
        command ~= " 2> /dev/null 1> /dev/null";

    unittest {
        version (Posix)
            command ~= " 2> /dev/null 1> /dev/null";
    }
}