There is an updated pull request by Piraty against master on the void-packages repository

https://github.com/Piraty/void-packages kernel-repro
https://github.com/void-linux/void-packages/pull/26775

Build kernels reproducibly
https://www.kernel.org/doc/html/v5.9/kbuild/reproducible-builds.html

[ci skip]

A patch file from https://github.com/void-linux/void-packages/pull/26775.patch is attached