swapon -s on the host reports nothing.
# pct config <redacted>
arch: amd64
cores: 2
description: <redacted>
features: fuse=1,nesting=1
hostname: host1
memory: 2048
net0: name=eth0,bridge=vmbr0,firewall=1,gw=<redacted>,hwaddr=<redacted>,ip=<redacted>/32,type=veth
onboot: 1
ostype: debian
rootfs...