So I got a linux (arch) vm up and running, installed wireshark, git, babeld, and bridge-tools (ip already installed).  Cloned babeld-lab, moved into that repository and called

sudo ./babeld-lab.sh add

as in step 1.

This is the error message I get:

vagrant@archlinux:~/babeld-lab$ sudo ./babeld-lab.sh add
RTNETLINK answers: Operation not supported
RTNETLINK answers: Operation not supported
add bridge failed: Package not installed
set stp status failed: No such device
interface veth-p0 does not exist!
interface veth-p1 does not exist!
Cannot create namespace file "/var/run/netns/n0": File exists
Cannot create namespace file "/var/run/netns/n1": File exists
Cannot find device "veth-n0"
Cannot find device "veth-n1"
Cannot find device "veth-n0"

For what it's worth, calling this again outputs

Cannot find device "veth-p0"
Cannot find device "veth-p1"
Cannot find device "veth-n0"
Cannot find device "veth-n1"
Cannot find device "br-babel"

I'll look through the file, but my bash is a bit rusty.

best,

Arthur