moby: arm builds missing from regular apt repo (1.12.1)

However, it is present in test, and experimental.

Expect: curl -fsSL https://get.docker.com/ | sh to install docker 1.12.1 as curl -fsSL https://test.docker.com/ | sh installed 1.12.1-rc2

Current script output:

$ curl -fsSL https://get.docker.com/ | sh
Warning: the "docker" command appears to already exist on this system.

If you already have Docker installed, this script can cause trouble, which is
why we're displaying this warning and provide the opportunity to cancel the
installation.

If you installed the current Docker package using this script and are using it
again to update Docker, you can safely ignore this message.

You may press Ctrl+C now to abort this script.
+ sleep 20
modprobe: FATAL: Module aufs not found.
Warning: current kernel is not supported by the linux-image-extra-virtual
 package.  We have no AUFS support.  Consider installing the packages
 linux-image-virtual kernel and linux-image-extra-virtual for AUFS support.
+ sleep 10
+ sudo -E sh -c apt-key adv --keyserver hkp://ha.pool.sks-keyservers.net:80 --recv-keys 58118E89F3A912897C070ADBF76221572C52609D
Executing: gpg --ignore-time-conflict --no-options --no-default-keyring --homedir /tmp/tmp.QXDupgA82l --no-auto-check-trustdb --trust-model always --keyring /etc/apt/trusted.gpg --primary-keyring /etc/apt/trusted.gpg --keyserver hkp://ha.pool.sks-keyservers.net:80 --recv-keys 58118E89F3A912897C070ADBF76221572C52609D
gpg: requesting key 2C52609D from hkp server ha.pool.sks-keyservers.net
gpg: key 2C52609D: "Docker Release Tool (releasedocker) <docker@docker.com>" not changed
gpg: Total number processed: 1
gpg:              unchanged: 1
+ break
+ sudo -E sh -c apt-key adv -k 58118E89F3A912897C070ADBF76221572C52609D >/dev/null
+ sudo -E sh -c mkdir -p /etc/apt/sources.list.d
+ dpkg --print-architecture
+ sudo -E sh -c echo deb \[arch=armhf\] https://apt.dockerproject.org/repo debian-jessie main > /etc/apt/sources.list.d/docker.list
+ sudo -E sh -c sleep 3; apt-get update; apt-get install -y -q docker-engine
Hit http://archive.raspberrypi.org jessie InRelease
Hit http://mirrordirector.raspbian.org jessie InRelease
Hit https://apt.dockerproject.org debian-jessie InRelease
Hit http://archive.raspberrypi.org jessie/main armhf Packages
Hit http://mirrordirector.raspbian.org jessie/main armhf Packages
Hit https://apt.dockerproject.org debian-jessie/main armhf Packages
Hit http://mirrordirector.raspbian.org jessie/contrib armhf Packages
Get:1 https://apt.dockerproject.org debian-jessie/main Translation-en_US [454 B]
Hit http://mirrordirector.raspbian.org jessie/non-free armhf Packages
Get:2 https://apt.dockerproject.org debian-jessie/main Translation-en [454 B]
Hit http://mirrordirector.raspbian.org jessie/rpi armhf Packages
Hit https://packagecloud.io jessie InRelease
Hit https://packagecloud.io jessie InRelease
Hit https://packagecloud.io jessie/main armhf Packages
Get:3 https://packagecloud.io jessie/main Translation-en_US [162 B]
Ign http://archive.raspberrypi.org jessie/main Translation-en_US
Ign http://archive.raspberrypi.org jessie/main Translation-en
Ign http://mirrordirector.raspbian.org jessie/contrib Translation-en_US
Ign http://mirrordirector.raspbian.org jessie/contrib Translation-en
Ign http://mirrordirector.raspbian.org jessie/main Translation-en_US
Ign http://mirrordirector.raspbian.org jessie/main Translation-en
Ign http://mirrordirector.raspbian.org jessie/non-free Translation-en_US
Ign http://mirrordirector.raspbian.org jessie/non-free Translation-en
Ign http://mirrordirector.raspbian.org jessie/rpi Translation-en_US
Ign http://mirrordirector.raspbian.org jessie/rpi Translation-en
Get:4 https://apt.dockerproject.org debian-jessie/main Translation-en_US [454 B]
Get:5 https://packagecloud.io jessie/main Translation-en [162 B]
Get:6 https://apt.dockerproject.org debian-jessie/main Translation-en [454 B]
Get:7 https://apt.dockerproject.org debian-jessie/main Translation-en_US [454 B]
Get:8 https://apt.dockerproject.org debian-jessie/main Translation-en [454 B]
Get:9 https://apt.dockerproject.org debian-jessie/main Translation-en_US [454 B]
Hit https://packagecloud.io jessie/main armhf Packages
Get:10 https://apt.dockerproject.org debian-jessie/main Translation-en [454 B]
Get:11 https://packagecloud.io jessie/main Translation-en_US [162 B]
Get:12 https://apt.dockerproject.org debian-jessie/main Translation-en_US [454 B]
Ign https://apt.dockerproject.org debian-jessie/main Translation-en_US
Get:13 https://packagecloud.io jessie/main Translation-en [162 B]
Get:14 https://apt.dockerproject.org debian-jessie/main Translation-en [454 B]
Ign https://apt.dockerproject.org debian-jessie/main Translation-en
Get:15 https://packagecloud.io jessie/main Translation-en_US [162 B]
Get:16 https://packagecloud.io jessie/main Translation-en [162 B]
Get:17 https://packagecloud.io jessie/main Translation-en_US [162 B]
Get:18 https://packagecloud.io jessie/main Translation-en [162 B]
Get:19 https://packagecloud.io jessie/main Translation-en_US [162 B]
Get:20 https://packagecloud.io jessie/main Translation-en [162 B]
Get:21 https://packagecloud.io jessie/main Translation-en_US [162 B]
Get:22 https://packagecloud.io jessie/main Translation-en [162 B]
Get:23 https://packagecloud.io jessie/main Translation-en_US [162 B]
Get:24 https://packagecloud.io jessie/main Translation-en [162 B]
Get:25 https://packagecloud.io jessie/main Translation-en_US [162 B]
Get:26 https://packagecloud.io jessie/main Translation-en [162 B]
Get:27 https://packagecloud.io jessie/main Translation-en_US [162 B]
Ign https://packagecloud.io jessie/main Translation-en_US
Get:28 https://packagecloud.io jessie/main Translation-en [162 B]
Ign https://packagecloud.io jessie/main Translation-en
Get:29 https://packagecloud.io jessie/main Translation-en_US [162 B]
Ign https://packagecloud.io jessie/main Translation-en_US
Get:30 https://packagecloud.io jessie/main Translation-en [162 B]
Ign https://packagecloud.io jessie/main Translation-en
Reading package lists... Done
Reading package lists...
Building dependency tree...
Reading state information...
docker-engine is already the newest version.
0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.
+ sudo -E sh -c docker version
Client:
 Version:      1.12.1-rc2
 API version:  1.24
 Go version:   go1.6.3
 Git commit:   236317f
 Built:        Wed Aug 17 05:04:46 2016
 OS/Arch:      linux/arm

Server:
 Version:      1.12.1-rc2
 API version:  1.24
 Go version:   go1.6.3
 Git commit:   236317f
 Built:        Wed Aug 17 05:04:46 2016
 OS/Arch:      linux/arm

If you would like to use Docker as a non-root user, you should now consider
adding your user to the "docker" group with something like:

  sudo usermod -aG docker <user>

Remember that you will have to log out and back in for this to take effect!