Right now you can do g_object_new(SOUP_TYPE_SESSION, NULL) even if you are not supposed to do it and gobject does not give a warning because the class is not marked as an abstract class.

I discovered this (with Dan's help) when running this piece of javascript code:

const Soup = imports.gi.Soup;

let session = new Soup.Session ();
let status = session.send_message(Soup.Message.new ('GET', 'http://www.google.com'));
print (status);


because this is my first libsoup programm and I forget to use Soup.SessionSync instead of Soup.Session.

Marking SoupSession as abstract class would have saved me a nice time :-)