The RFS ticket #1054258 / https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1054258 aims to correct errors and substitute `ruby-mdl` by `mdl` for good. Thus, the uploaded to mentors.debian.net by 2023-10-29 finally uses only one control file in common to assemble both `ruby-mdl` as the transition dummy package, and `mdl` as the one where further curated in future.