Prevents OSX firewall allow-this-application-to-accept-inbound-connections permission popups and is generally safer.
To test, make an arbitrary whitespace change to src/bitcoind.cpp
and recompile. This normally resets the firewall’s memory.
Easiest way to reproduce a popup without running the test suite:
0src/bitcoind -regtest -bind=127.0.0.1 # No popup
1src/bitcoind -regtest # Popup