sandbox + v3 onion service gives
an attempt to setup a v3 onion service using this shell script: https://github.com/toralf/torutils/blob/7228f04b22008cb65156b7b98efa4fa64ff3477a/os.sh gives at a stable Gentoo hardened Linux with Tor 0.3.2.9 :
[err] sandbox_getaddrinfo(): Bug: (Sandbox) failed to get address mr-fox!