I’m having some issues with dispatcher and cannot get why it’s not working

Idea is to use ds_next_dst right after ds_select_dst

I’m having it like this

modparam("dispatcher", "list_file", "/tmp/dispatcher.list")
modparam("dispatcher", "flags", 2) # Enable dispather failover
modparam("dispatcher", "xavp_dst", "_dispacher_dst_list_")

…

ds_select_dst(«1», «0»);

… 

# Some extra check on $du here

…

ds_next_dst();

But get in logs 

WARNING: dispatcher [dispatch.c:2285]: ds_update_dst(): no xavp uri field in next destination record

But contents of /tmp/dispatcher.list is

1 sip:172.28.0.12:5060
1 sip:172.28.0.19:5060

Can I somehow dump xavp_dst var to check if ds_select_dst is correct?

kamailio 5.2.0-dev6