Nightly build for OpenSuSE Leap 15.1 not installable / broken requirements

With the following repository active on Leap 15.1:

17 | ring                                 | Ring 15.1 - x86_64 - ring          | Yes     | ( p) Yes  | Yes      |   99     | rpm-md | https://dl.jami.net/ring-nightly/opensuse-leap_15.1                                   | 

When trying to update Jami I get failed dependencies.

zypper up jami
Loading repository data...
Reading installed packages...
Resolving package dependencies...

Problem: nothing provides libQt5Core.so.5(Qt_5.12)(64bit) needed by jami-20201002.3.a4d29d2-1.x86_64
 Solution 1: do not install jami-20201002.3.a4d29d2-1.x86_64
 Solution 2: break jami-20201002.3.a4d29d2-1.x86_64 by ignoring some of its dependencies

This is the current libQt5Core of 15.1:

# zypper se -i -s libqt5core 
Loading repository data...
Reading installed packages...

S  | Name             | Type    | Version           | Arch   | Repository
---+------------------+---------+-------------------+--------+-----------------------
i+ | libQt5Core-devel | package | 5.9.7-lp151.4.6.1 | x86_64 | Main Update Repository
i  | libQt5Core5      | package | 5.9.7-lp151.4.6.1 | x86_64 | Main Update Repository

The version I used to be running is jami-20200630.1.5c91b4a-1.x86_64, however it crashes on startup since a couple of weeks, now.

Can you check for which version of OpenSuSE you are actually building, or whether any additional repository is required for installation, please.

Kind regards,Alex