While I was testing Leap 15.6 beta (630.1-boot)
I saw this error in /var/log/zypp history:

# 2024-03-15 00:17:14 trousers-0.3.15-150600.7.1.x86_64.rpm installed ok
# Additional rpm output:
# Group 'mail' not found. Creating the user mailbox file with 0600 mode.
# /var/tmp/rpm-tmp.pxRHp2: line 24: /usr/bin/udevadm: No such file or directory
# 
2024-03-15
00:17:14|install|trousers|0.3.15-150600.7.1|x86_64||openSUSE-Leap-15.6-1|6462c0eebacd6db401e9c14dbcd79d22e914197ef0716fa9bef3a3476715d8c69bdf65b0b5fbc3a43c42be70277bf3f3d00881c6b6fd41bba174b8c77b8941f5|

A similar problem was fixed in tumbleweed with SR#1135798

For Leap 15.6 and 15.5 the change in the spec file should be:

 Requires(pre):  pwdutils
+Requires(pre):  coreutils
+Requires(post): udev
 BuildRoot:      %{_tmppath}/%{name}-%{version}-build