This branch in the 'bro' repo allows running unit tests with the default listen address set to 127.0.0.1 versus the default of binding to all available IPs. The later, on macOS, is annoying for those with the firewall enabled as it spawns a stream of popup dialogues that steal keyboard focus. Generally, we don't need/want to listen on externally-reachable IPs anyway.
I also split out some contents of init-bare.bro to a separate script as that's needed to be able to call getenv() inside a variable initialization in the broker framework. (See the "gross hack" comment regarding init_builtin_funcs() in scan.l).