You can check which process is running using e.g. ps faux | less
. Scroll down to find the lxc-start
process corresponding to your container, and see what is running under it (the f
flag triggers a forest display which should show in a pretty obvious way which processes belong to the container).
Then, you can use strace -fp <pid>
to attach to the last running process in that container and see what it is doing.
Last but not least, you can try to break down the command in 2 or 3 phases. In the (unlikely) case where the problem would come from a package prompting you for input (which shouldn't happen since you specified the noninteractive
front-end, but who knows) that will help to single it out.