It works for me:

scroll@ivy:~$ sudo add-apt-repository ppa:ci-train-ppa-service/3521
[sudo] password for scroll: 
 https://bileto.ubuntu.com/#/ticket/3521

https://objectstorage.prodstack4-5.canonical.com/v1/AUTH_39a8dbb93caf4ec889f8a1b7f69885db/bileto-3521/2018-11-16_06:34:48/bionic_osinfo-db_content.diff (52531 lines)
https://objectstorage.prodstack4-5.canonical.com/v1/AUTH_39a8dbb93caf4ec889f8a1b7f69885db/bileto-3521/2018-11-16_06:34:48/bionic_osinfo-db_packaging_changes.diff (240 lines)
 More info: https://launchpad.net/~ci-train-ppa-service/+archive/ubuntu/3521
Press [ENTER] to continue or Ctrl-c to cancel adding it.

Hit:1 http://security.ubuntu.com/ubuntu bionic-security InRelease
Hit:2 http://archive.ubuntu.com/ubuntu bionic InRelease
Get:3 http://ppa.launchpad.net/ci-train-ppa-service/3521/ubuntu bionic InRelease [20.8 kB]
Hit:4 http://archive.ubuntu.com/ubuntu bionic-updates InRelease                      
Hit:5 http://archive.ubuntu.com/ubuntu bionic-backports InRelease                   
Get:6 http://ppa.launchpad.net/ci-train-ppa-service/3521/ubuntu bionic/main amd64 Packages [508 B]
Get:7 http://ppa.launchpad.net/ci-train-ppa-service/3521/ubuntu bionic/main Translation-en [364 B]
Fetched 21.6 kB in 1s (15.2 kB/s)                   
Reading package lists... Done

scroll@ivy:~$ sudo apt-get update
Hit:1 http://archive.ubuntu.com/ubuntu bionic InRelease
Hit:2 http://security.ubuntu.com/ubuntu bionic-security InRelease
Hit:3 http://ppa.launchpad.net/ci-train-ppa-service/3521/ubuntu bionic InRelease
Hit:4 http://archive.ubuntu.com/ubuntu bionic-updates InRelease
Hit:5 http://archive.ubuntu.com/ubuntu bionic-backports InRelease
Reading package lists... Done                      

scroll@ivy:~$ sudo apt install osinfo-db 
Reading package lists... Done
Building dependency tree       
Reading state information... Done
The following packages will be upgraded:
  osinfo-db
1 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.
Need to get 76.7 kB of archives.
After this operation, 220 kB of additional disk space will be used.
Get:1 http://ppa.launchpad.net/ci-train-ppa-service/3521/ubuntu bionic/main amd64 osinfo-db all 0.20180929-1ubuntu0.1 [76.7 kB]
Fetched 76.7 kB in 1s (129 kB/s)     
(Reading database ... 225419 files and directories currently installed.)
Preparing to unpack .../osinfo-db_0.20180929-1ubuntu0.1_all.deb ...
Unpacking osinfo-db (0.20180929-1ubuntu0.1) over (0.20180226-1) ...
Setting up osinfo-db (0.20180929-1ubuntu0.1) ...

scroll@ivy:~$ sudo osinfo-query os | grep ubuntu18.04
 ubuntu18.04          | Ubuntu 18.04 LTS                                   | 18.04    | http://ubuntu.com/ubuntu/18.04          

scroll@ivy:~/kvm$ sudo virt-install \
>   --name=scroll-test \
>   --hvm \
>   --ram=2048 \
>   --vcpus=2 \
>   --os-variant=ubuntu18.04 \
>   --os-type linux \
>   --disk path=/home/scroll/kvm/scroll-test.img \
>   --cdrom=/home/scroll/kvm/scroll-test-cloud-init.iso \
>   --graphics vnc \
>   --graphics spice \
>   --noautoconsole \
>   --os-type=linux \
>   --network bridge:br0 \
>   --network bridge:virbr0

Starting install...
Domain installation still in progress. You can reconnect to 
the console to complete the installation process.

scroll@ivy:~/kvm$ sudo virsh list | grep scroll-test
 1     scroll-test                    running