libidn2-0-32bit cannot be installed on Leap:

zypper in -r oss libidn2-0-32bit
Loading repository data...
Reading installed packages...
Resolving package dependencies...

Problem: nothing provides libunistring.so.0 needed by
libidn2-0-32bit-2.0.2-1.1.x86_64
 Solution 1: do not install libidn2-0-32bit-2.0.2-1.1.x86_64
 Solution 2: break libidn2-0-32bit-2.0.2-1.1.x86_64 by ignoring some of its
dependencies

This was fixed in Factory:
https://build.opensuse.org/request/show/448698

Beaks a maintenance update for libidn2 on Leap:
https://openqa.opensuse.org/tests/476836#step/install_packages/9

Plan is to backport this change to Leap, will also submit to SLE.