I started from scratch and installed http://archlinuxarm.org/os/ArchLinuxARM ... est.tar.gz
And here is my full history from the BBB:
$this->bbcode_second_pass_code('', '[root@alarm tmp]# history
1 df -h
2 pacman -Syy
3 pacman -S docker lxc
4 systemctl start docker
5 docker images
6 cd /tmp/
7 pacman -S wget
8 wget http://os.archlinuxarm.org/os/ArchLinuxARM-armv7-latest.tar.gz
9 cat ArchLinuxARM-armv7-latest.tar.gz | docker import - alarm/armv7:latest
10 docker run -i -t alarm/armv7 /bin/bash')
It still fails with the same error. There must be something I'm missing.