[HTC J Butterfly 3] Error building mkbootimg - tools/metalava/manual not found

[NVriezen]

Now I'm stuck at a new point. Which is that android lxc won't start.
The device gives me the following error when trying to start it manually:

root@ubuntu-phablet:~# lxc-start -n android -F
lxc-start: conf.c: mount_entry: 1858 No such file or directory - Failed to mount "tmpfs" on "/usr/lib/aarch64-linux-gnu/lxc/dev"
lxc-start: conf.c: lxc_setup: 3335 failed to setup the mount entries for 'android'
lxc-start: start.c: do_start: 1248 Failed to setup container "android".
lxc-start: sync.c: __sync_wait: 59 An error occurred in another process (expected sequence number 5)
lxc-start: start.c: __lxc_start: 1802 Failed to spawn container "android".

The container failed to start.
Additional information can be obtained by setting the --logfile and --logpriority options.

In the dmesg log I already saw that the camera and audio will not work.
But that is really something for later.
First I want to get the GUI running or just the system in general.
I also can't reboot the device through the shell anymore.
Making your own system image definitely is the harder way to port UT.