I am running sshuttle as:

/usr/bin/sshuttle -e ssh --to-ns=10.8.0.10 --to-ns=10.8.0.23 --no-latency-control -l 12304 --ns-hosts 127.10.0.4 -Nr [redacted]@host.example.com 10.8.0.0/16 10.12.0.0/16

but it's telling me:

WARNING: --to-ns option is ignored because --dns was not used.

If I omit the --to-ns=10.8.0.10 --to-ns=10.8.0.23 arguments, everything works as expected. I am not sure I see why adding to that working configuration an instruction for sshuttle to ignore the remote /etc/resolv.conf and instead use the remote NSes that I tell it to should require --dns and therefore be incompatible with --ns-hosts.