Example of an echo server from vibed.org:

import vibe.d;

shared static this()
{
    listenTCP(7000, (conn) { conn.write(conn); });
}

It works for me. But if I am trying to add this ctor to one my project it isn't work: it listens and allows to connect, but delegate isn't executed (checked by assert(false) at first line of it). And after killing of this process it just releases connected socket by disconnecting client (telnet has been used as client).

What could be the problem?