its --with-new-pkgs

apt-private/private-cmndline.cc

@@ -125,7 +125,7 @@ bool addArgumentsAPTGet(std::vector<CommandLine::Args> &Args, char const * const
       addArg(0, "solver", "APT::Solver", CommandLine::HasArg);
       if (CmdMatches("upgrade"))
       {
-         addArg(0, "allow-new", "APT::Get::Upgrade-Allow-New", 
+         addArg(0, "new-pkgs", "APT::Get::Upgrade-Allow-New", 
                 CommandLine::Boolean);
       }
    }