dl-ubuntu-test-iso doesn't work on current Ubuntu Desktop 20.10 Alpha

[ato]

Silent - no info - no debug:

$ cat /etc/os-release
NAME="Ubuntu"
VERSION="20.10 (Groovy Gorilla)"
ID=ubuntu
ID_LIKE=debian
PRETTY_NAME="Ubuntu Groovy Gorilla (development branch)"
VERSION_ID="20.10"
HOME_URL="https://www.ubuntu.com/"
SUPPORT_URL="https://help.ubuntu.com/"
BUG_REPORT_URL="https://bugs.launchpad.net/ubuntu/"
PRIVACY_POLICY_URL="https://www.ubuntu.com/legal/terms-and-policies/privacy-policy"
VERSION_CODENAME=groovy
UBUNTU_CODENAME=groovy

$ sudo snap install dl-ubuntu-test-iso
dl-ubuntu-test-iso 20200429 from Jean-Baptiste Lallement (jibel) installed

$ snap info dl-ubuntu-test-iso
name: dl-ubuntu-test-iso
summary: Easily download daily Ubuntu and flavours ISOs
publisher: Jean-Baptiste Lallement (jibel)
store-url: https://snapcraft.io/dl-ubuntu-test-iso
contact: <email address hidden>

$ dl-ubuntu-test-iso -d --flavor=ubuntu --variant=server --arch=amd64 --release=focal --build=pending --isoroot=/tmp/iso/

Silent - no output

Slitly more info starting from source:

$ git clone .......

$ /repo/ubuntu-qa-tools/dl-ubuntu-test-iso/dl-ubuntu-test-iso -d --flavor=ubuntu --variant=server --arch=amd64 --release=focal --build=pending --isoroot=/tmp/iso/
Warning! zsync is not installed, falling back to rsync

Installing zsync doesn't help