mjhjmtu

I am using Debian testing and I followed this instructions how to install docker on Debian. However, I got an error during the installation:

$ sudo apt-get install docker-ce
Reading package lists... Done
Building dependency tree 
Reading state information... Done
The following packages were automatically installed and are no longer required:
 gnome-orca libgdbm3 libmpfr4 libplacebo3
Use 'sudo apt autoremove' to remove them.
The following additional packages will be installed:
 aufs-dkms aufs-tools cgroupfs-mount dkms linux-headers-amd64 linux-kbuild-4.15
Suggested packages:
 aufs-dev python3-apport menu
The following NEW packages will be installed:
 aufs-dkms aufs-tools cgroupfs-mount dkms docker-ce linux-headers-amd64 linux-kbuild-4.15
0 upgraded, 7 newly installed, 0 to remove and 1 not upgraded.
Need to get 30.8 MB of archives.
After this operation, 152 MB of additional disk space will be used.
Do you want to continue? [Y/n] y
Get:1 http://mirror.aarnet.edu.au/debian buster/main amd64 dkms all 2.3-3 [74.9 kB]
Get:2 http://mirror.aarnet.edu.au/debian buster/main amd64 linux-kbuild-4.15 amd64 4.15.4-1 [765 kB]
Get:3 http://mirror.aarnet.edu.au/debian buster/main amd64 aufs-dkms amd64 4.15+20180219-1 [179 kB]
Get:4 http://mirror.aarnet.edu.au/debian buster/main amd64 aufs-tools amd64 1:4.9+20170918-1 [104 kB]
Get:5 http://mirror.aarnet.edu.au/debian buster/main amd64 cgroupfs-mount all 1.4 [6,276 B]
Get:6 http://mirror.aarnet.edu.au/debian buster/main amd64 linux-headers-amd64 amd64 4.14+89 [6,208 B]
Get:7 https://download.docker.com/linux/debian buster/stable amd64 docker-ce amd64 17.12.1~ce-0~debian [29.7 MB]
Fetched 30.8 MB in 18s (1,688 kB/s) 
Selecting previously unselected package dkms.
(Reading database ... 127936 files and directories currently installed.)
Preparing to unpack .../0-dkms_2.3-3_all.deb ...
Unpacking dkms (2.3-3) ...
Selecting previously unselected package linux-kbuild-4.15.
Preparing to unpack .../1-linux-kbuild-4.15_4.15.4-1_amd64.deb ...
Unpacking linux-kbuild-4.15 (4.15.4-1) ...
Selecting previously unselected package aufs-dkms.
Preparing to unpack .../2-aufs-dkms_4.15+20180219-1_amd64.deb ...
Unpacking aufs-dkms (4.15+20180219-1) ...
Selecting previously unselected package aufs-tools.
Preparing to unpack .../3-aufs-tools_1%3a4.9+20170918-1_amd64.deb ...
Unpacking aufs-tools (1:4.9+20170918-1) ...
Selecting previously unselected package cgroupfs-mount.
Preparing to unpack .../4-cgroupfs-mount_1.4_all.deb ...
Unpacking cgroupfs-mount (1.4) ...
Selecting previously unselected package docker-ce.
Preparing to unpack .../5-docker-ce_17.12.1~ce-0~debian_amd64.deb ...
Unpacking docker-ce (17.12.1~ce-0~debian) ...
Selecting previously unselected package linux-headers-amd64.
Preparing to unpack .../6-linux-headers-amd64_4.14+89_amd64.deb ...
Unpacking linux-headers-amd64 (4.14+89) ...
Setting up aufs-tools (1:4.9+20170918-1) ...
Setting up linux-kbuild-4.15 (4.15.4-1) ...
Setting up docker-ce (17.12.1~ce-0~debian) ...
Created symlink /etc/systemd/system/multi-user.target.wants/docker.service → /lib/systemd/system/docker.service.
Created symlink /etc/systemd/system/sockets.target.wants/docker.socket → /lib/systemd/system/docker.socket.
Setting up linux-headers-amd64 (4.14+89) ...
Setting up cgroupfs-mount (1.4) ...
Setting up dkms (2.3-3) ...
Processing triggers for libc-bin (2.27-2) ...
Processing triggers for systemd (238-2) ...
Processing triggers for man-db (2.8.2-1) ...
Setting up aufs-dkms (4.15+20180219-1) ...
Loading new aufs-4.15+20180219 DKMS files...
Building for 4.14.0-3-amd64
Building initial module for 4.14.0-3-amd64
Error! The dkms.conf for this module includes a BUILD_EXCLUSIVE directive which
does not match this kernel/arch. This indicates that it should not be built.
Skipped.

What did I miss?

Thank you in advance