No network in chroot environment

[Ralf Mardorf]

For your purpose you could try if

  sudo systemd-nspawn -bqD /path/to/mount_point

does the job, instead of using a chroot.

You probably could do all you want to do and don't need to fear an
issue related to resolv.conf links, since using the "-b" option might be
enough.

Since Ubuntu tends to split bundles provided by upstream, you might need
to install the Ubuntu package "systemd-container" to get
"/usr/bin/systemd-nspawn". Just run

  sudo apt update
  sudo apt systemd-container