from post of openSUSE-repos 

Spec is available here
https://github.com/openSUSE/openSUSE-repos/blob/main/dist/package/openSUSE-repos.spec

Seems like installation is either not idempotent or fails if network is not
availabile.

This is how we call it in %post

ZYPP_READONLY_HACK=1 zypper addservice %{_datadir}/zypp/local/service/openSUSE
openSUSE

The repoindex used in post
https://github.com/openSUSE/openSUSE-repos/blob/main/opensuse-tumbleweed-repoindex.xml

[   27s] Executing(%clean): /bin/sh -e /var/tmp/rpm-tmp.AIoUiG
[   27s] + umask 022
[   27s] + cd /home/abuild/rpmbuild/BUILD
[   27s] + cd openSUSE-repos-20220924.30f80ef
[   27s] + /usr/bin/rm -rf
/home/abuild/rpmbuild/BUILDROOT/openSUSE-repos-20220924.30f80ef-lp155.1.1.s390x
[   27s] + exit 0
[   27s] ... checking for files with abuild user/group
[   27s] ... running 00-check-install-rpms
[   27s] ... installing all built rpms
[   27s] Preparing packages...
[   27s] openSUSE-repos-Leap-20220924.30f80ef-lp155.1.1.s390x
[   27s] openSUSE-repos-Tumbleweed-20220924.30f80ef-lp155.1.1.s390x
[   27s] Setting new service openSUSEindeterminate indeterminate
[   27s] Service 'openSUSE' has been successfully added.
[   27s] ... running 50-check-binary-kernel-log
[   27s] ... running 50-check-core-files
[   27s] ... checking for core files
[   27s] ... running 50-check-debuginfo
[   27s] ... testing for empty debuginfo packages
[   27s] ... running 50-check-filelist
[   27s] ... checking filelist
[   27s] ... running 50-check-gconf-scriptlets
[   28s] ... testing GConf scriptlet presence
[   28s] ... running 50-check-installtest
[   28s] ... testing for pre/postinstall scripts that are not idempotent
[   28s] Setting new service openSUSEindeterminate indeterminate
[   28s] Error occurred while adding service 'openSUSE'.
[   28s] postinstall script of
openSUSE-repos-Tumbleweed-20220924.30f80ef-lp155.1.1.s390x.rpm failed
[   28s] ### VM INTERACTION START ###
[   28s] [   24.397465][    T1] sysrq: Power Off
[   28s] [   24.397956][  T111] reboot: Power down
[   29s] ### VM INTERACTION END ###
[   29s] 
[   29s] s390zp24 failed "build openSUSE-repos.spec" at Sat Sep 24 13:07:20 UTC
2022.