The reason this seems so weirdly hard is that you're not supposed to be doing it. You provide sources and instructions on how to build them, and then your job is done. Users can follow those instructions. If you want to you can also build a binary with an old version of libc and distribute that to help users who don't want to compile it themselves.
Packaging it for a distro is someone else's job, and they'll take care of concerns like Debian's dependency policy. If they want to package it in the first place of course.
Packaging it for a distro is someone else's job, and they'll take care of concerns like Debian's dependency policy. If they want to package it in the first place of course.