With the following configuration unbound 1.12.0-1 cannot start on Raspberry Pi 4 with kernel 5.4.80-1-ARCH.
$this->bbcode_second_pass_code('', '
# vim: ft=conf
server:
	use-syslog: yes
	do-daemonize: no
	username: "unbound"
	directory: "/etc/unbound"
	trust-anchor-file: "trusted-key.key"
	root-hints: "root.hints"
	tls-cert-bundle: "/etc/ssl/certs/ca-certificates.crt"
	interface: 0.0.0.0
	access-control: 0.0.0.0/0	refuse
	access-control: 127.0.0.1	allow
	access-control: 192.168.1.0/24	allow
')
The following are the error by systemd.
$this->bbcode_second_pass_code('', '
● unbound.service - Validating, recursive, and caching DNS resolver
     Loaded: loaded (/etc/systemd/system/unbound.service; enabled; vendor preset: disabled)
     Active: failed (Result: exit-code) since Sat 2020-12-05 00:48:08 PST; 4s ago
       Docs: man:unbound(8)
    Process: 19615 ExecStart=/usr/bin/unbound -d -p (code=exited, status=1/FAILURE)
   Main PID: 19615 (code=exited, status=1/FAILURE)
Dec 05 00:48:07 rpi4b.acaena.internal systemd[1]: Starting Validating, recursive, and caching DNS resolver...
Dec 05 00:48:08 rpi4b.acaena.internal unbound[19615]: [1607158088] unbound[19615:0] error: failed to list interfaces: getifaddrs: Address family not supported by protocol
Dec 05 00:48:08 rpi4b.acaena.internal unbound[19615]: [1607158088] unbound[19615:0] fatal error: could not open ports
Dec 05 00:48:08 rpi4b.acaena.internal systemd[1]: unbound.service: Main process exited, code=exited, status=1/FAILURE
Dec 05 00:48:08 rpi4b.acaena.internal systemd[1]: unbound.service: Failed with result 'exit-code'.
Dec 05 00:48:08 rpi4b.acaena.internal systemd[1]: Failed to start Validating, recursive, and caching DNS resolver.
')
			
		