srsenb crash on startup

[kistlin]

My goal is to run a simple 4G setup.
When running srsenb I use pretty much default configurations.
enb.conf changes are only TX gain, more verbose logging and pcap logging.
rr.conf unchanged.

Now when running srsenb it crashes from what looks like the empty

nr_cell_list =
(
  // no NR cells
);

In srsenb/src/enb.cc it crashes at

  if (ret == SRSRAN_SUCCESS) {
    if (tmp_phy->init(args.phy, phy_cfg, tmp_radio.get(), tmp_eutra_stack.get(), *tmp_nr_stack, this)) {

when dereferencing tmp_nr_stack, which is a nullptr.
It's nullptr, because

  if (not rrc_nr_cfg.cell_list.empty()) {
    // add NR stack
    tmp_nr_stack.reset(new gnb_stack_nr(log_sink));

is never entered due to the empty nr_cell_list.
So what am I supposed to configure there?
It looks like as soon as I do that, that I need to define a second rf_port?
Can I still run this on an Ettus Research B205mini-i?
I'm on commit 1fab3df.