ruby2.5-rubygem-unf_ext.s390x: W: description-shorter-than-summary
rubygem-unf_ext.src: W: description-shorter-than-summary
The package description should be longer than the summary. be a bit more
verbose, please.

ruby2.5-rubygem-unf_ext.s390x: W: hidden-file-or-dir /usr/lib64/ruby/gems/2.5.0/gems/unf_ext-0.0.7.5/.document
ruby2.5-rubygem-unf_ext.s390x: W: hidden-file-or-dir /usr/lib64/ruby/gems/2.5.0/gems/unf_ext-0.0.7.5/.travis.yml
ruby2.5-rubygem-unf_ext.s390x: W: hidden-file-or-dir /usr/lib64/ruby/gems/2.5.0/gems/unf_ext-0.0.7.5/ext/unf_ext/.sitearchdir.time
The file or directory is hidden. You should see if this is normal, and delete
it from the package if not.

ruby2.5-rubygem-unf_ext.s390x: W: version-control-internal-file /usr/lib64/ruby/gems/2.5.0/gems/unf_ext-0.0.7.5/.gitignore
You have included file(s) internally used by a version control system in the
package. Move these files out of the package and rebuild it.

ruby2.5-rubygem-unf_ext.s390x: W: zero-length /usr/lib64/ruby/gems/2.5.0/extensions/s390x-linux/2.5.0/unf_ext-0.0.7.5/gem.build_complete
ruby2.5-rubygem-unf_ext.s390x: W: zero-length /usr/lib64/ruby/gems/2.5.0/gems/unf_ext-0.0.7.5/ext/unf_ext/.sitearchdir.time
4 packages and 0 specfiles checked; 0 errors, 8 warnings.