I wanted to package the software unicorn:
https://build.opensuse.org/package/show/home:AdaLovelace:branches:Virtualization/unicorn

I have received some support to get it working with integrated pip for x86.
Anyways it is failing for all the other architectures with the following error:
[  215s] Using pip 23.3.2 from /usr/lib/python3.9/site-packages/pip (python 3.9)
[  215s] Looking in links: ./build
[  215s] ERROR: Could not find a version that satisfies the requirement unicorn==2.0.1.post1 (from versions: none)
[  215s] ERROR: No matching distribution found for unicorn==2.0.1.post1
[  215s] error: Bad exit status from /var/tmp/rpm-tmp.L65eBJ (%install)

I went to my s390x VM in the LinuxONE Community Cloud to check, whether the software unicorn is available:
~> pip index versions unicorn
WARNING: pip index is currently an experimental command. It may be removed/changed in a future release without prior warning.
unicorn (2.0.1.post1)
Available versions: 2.0.1.post1, 2.0.1, 2.0.0, 1.0.3, 1.0.2, 1.0.1, 1.0.0

It seems, that there is a bug for using pip on other architectures besides x86.