zypper has recently stopped explaining problems with packages.  It states that
there is a problem, but it does not states the nature of the problem.

By contrast, if I try to upgrade the same packages in YaST2, I do get verbose
and helpful explanations of the problems.

I can reproduce the problem with libzypp-16.15.3-1.1.x86_64 and
zypper-1.13.31-1.1.x86_64.

Example command-line output:

$ sudo zypper dup
Warning: You are about to do a distribution upgrade with all enabled
repositories. Make sure these repositories are compatible before you continue.
See 'man zypper' for more information about this command.
Loading repository data...
Reading installed packages...
Computing distribution upgrade...
27 Problems:
Problem: problem with installed package claws-mail-3.15.1-0.x86_64
Problem: problem with installed package claws-mail-lang-3.15.1-0.noarch
Problem: problem with installed package dkms-2.3-4.1.noarch
Problem: problem with installed package k3b-17.04.3-12.1.x86_64
Problem: problem with installed package lame-3.99.5-1016.9.x86_64
Problem: problem with installed package libgmyth0-0.7.1-12.23.x86_64
Problem: problem with installed package libkcddb16-16.07.0-5.6.x86_64
Problem: problem with installed package libmad0-0.15.1b-1.31.x86_64
Problem: problem with installed package libmp3lame0-3.99.5-1016.9.x86_64
Problem: problem with installed package libnetcdf11-4.4.1-28.37.x86_64
Problem: problem with installed package libprotobuf9-2.6.1-5.1.x86_64
Problem: problem with installed package libtwolame0-0.3.13-3.3.x86_64
Problem: problem with installed package libuchardet0-0.0.6-2.1.x86_64
Problem: problem with installed package libxmlsec1-1-1.2.18-1.57.x86_64
Problem: problem with installed package libxmlsec1-nss1-1.2.18-1.57.x86_64
Problem: problem with installed package mpv-bash-completion-3.3.13-109.4.noarch
Problem: problem with installed package mpv-zsh-completion-0.26.0-109.4.noarch
Problem: problem with installed package python3-Markdown-2.6.8-31.5.noarch
Problem: problem with installed package python3-SecretStorage-2.3.1-2.6.noarch
Problem: problem with installed package python3-blinker-1.4-18.9.noarch
Problem: problem with installed package python3-bottle-0.12.13-27.3.noarch
Problem: problem with installed package python3-cups-1.9.72-5.12.x86_64
Problem: problem with installed package python3-feedgenerator-1.9-1.12.noarch
Problem: problem with installed package python3-keyring-10.2-1.8.noarch
Problem: problem with installed package python3-pelican-3.7.1-1.53.noarch
Problem: problem with installed package tar-1.29-5.3.x86_64
Problem: problem with installed package
xorg-x11-driver-video-7.6_1-223.1.x86_64

Problem: problem with installed package claws-mail-3.15.1-0.x86_64
 Solution 1: install claws-mail-3.15.0-1.3.x86_64 (with vendor change)
  obs://build.opensuse.org/home:psych0naut  -->  openSUSE

Choose the above solution using '1' or skip, retry or cancel [1/s/r/c] (c):