Though I understand that there are likely only dozens of us, my question is: what would the use of Buildpacks buy us for this specific use case?
Unfortunately the resulting image would be larger than just a single binary, but building it would be a lot easier and repeatable for other people working on the project. The base layers would be cached though so in practice it might not be that much larger on disk.
I looked into using bazel for doing similar things, and the biggest stumbling block is that bazel itself is a PITA to install on all platforms. May end up trying https://please.build/ at some point.
One thing I really like about bazel is the pkg rules.. I currently use fpm/goreleaser(nfpm) to build rpms for things, and it's nice having a single build tool that can build the app and spit out an rpm.