There are packages that have in their spec file:
  Requires(pre) pwdutils
The package pwdutils was last available in 12.2 and was replaced in 12.3 by
shadow.
Having Requires(pre) pwdutils in the spec file could sooner or later cause a
bug similar to 1127610.

Here is the list of src.rpm present in Leap 15.1 and tumbleweed that are
affected:
NetworkManager-openconnect amanda amavisd-new apt-cacher-ng atftp avahi
avahi-glib2 avahi-mono avahi-qt4 boinc-client cntlm colord crawl cyrus-imapd
ddclient dkimproxy fetchmail firebird fonehome gdm glibc gnome-robots hackrf
icingaweb2 keepalived knot libperseus-sdr libxtrxll lightdm lighttpd lldpd
lockdev mariadb minidlna motion mpd munge nagios nginx nrpe ntp ntpsec openssh
otrs pcsc-lite pdns-common pdns-recursor pesign polkit postfixadmin postgresql
pound prosody pulseaudio quagga quassel rabbitmq-server salt shibboleth-sp
slurm sphinx subversion tftp tpm2-0-tss tpm2.0-abrmd trousers usbmuxd
virtualbox zabbix

Affected packages only in Leap 15.1:
ptokax

Affected packages only in tumbleweed:
influxdb khunphan syncthing(syncthing-relaysrv)

I'm wondering if this is the proper way to submit such kind of 'cumulative'
bug, or I should have opened a bug for every single package.