These aren’t well established where you can see the post was created in ’18. If they were established, you would seem them in the raw https://raw.githubusercontent.com/NixOS/nixpkgs/master/CONTRIBUTING.md. You can see folks having issues with using Discourse as a mailing list since it doesn’t quite work as expected & still requires review by someone with merge access to the primary repository. There is a SourceHut one that actually has some activity & I believe was once listed under the one of the contributing guides, but I can’t remember where it was listed. I doubt many maintainers are properly checking their email too despite listing them on the maintainer.nix file. I would hedge to say that unless the community migrates away, you would see folks complaining the tread above about disliking that there is no pull requests with instead push to the default branch so we would asume all contributions in practices will be expected to be done thru MS GitHub. As it stands going thru the mailing list puts a lot of friction on everyone & wastes time of other maintainers that are expected to then raise a PR on your behalf for review. Say that PR does get opened on your behalf, now you want to follow it since it’s your patch… well too bad since MS GitHub has no way of subscribing to PR threads like it does some aspects of by adding .atom to the end of a URL. As such, if you really want the in-practice option to not be under Microsoft’s domain, you’ll need to remove Microsoft from being the primary forge, relegating it to a mirror or dropping it outright.