Mount error when running distrobuilder inside a container

I need some help. I get the error below regardless if the container is privileged or not. Any advise would be appreciated.

[root@build-arch ~]# distrobuilder build-lxd distrobuilder/doc/examples/centos

mount: /tmp/distrobuilder/iso: mount failed: Operation not permitted.
Error: Error while downloading source: exit status 1

[denis@T450s ~]$ lxc config show build-arch
architecture: x86_64
config:
image.architecture: amd64
image.description: Archlinux current amd64 (20190317_04:18)
image.os: Archlinux
image.release: current
image.serial: “20190317_04:18”
security.privileged: “true”
volatile.base_image: d779d565736c7d365135d36816a8b98e90b3804fd434b9326f55e11d162b741e
volatile.eth0.hwaddr: 00:16:3e:5f:b7:06
volatile.idmap.base: “0”
volatile.idmap.next: ‘[]’
volatile.last_state.idmap: ‘[]’
volatile.last_state.power: RUNNING
devices: {}
ephemeral: false
profiles:

  • default
    stateful: false
    description: “”

Your container is missing loop devices, you need a few of the /dev/loopX devices present in there for loop mounting to work.

I added the unix-blocks loop0 to loop7 + the unix-char loop-control to the container and it worked as it was instructed in another thread: https://github.com/lxc/lxd/issues/2980

Thanks!