Sometime between Linux 5.15 and 6.1 (probably 5.17?), mounting a network address as a 9p filesystem came to require the mount option
-o trans=tcp. Without it, mount now fails with the error message:
mount: /mnt: special device 127.0.0.1 does not exist.
9pnet_virtio: no channels available for device 127.0.0.1