❯ rg ruby_3_0
pkgs/servers/mastodon/default.nix
2:, yarn, callPackage, imagemagick, ffmpeg, file, ruby_3_0, writeShellScript
23:    ruby = ruby_3_0;

pkgs/servers/http/unit/default.nix
8:, withRuby_3_0 ? false, ruby_3_0
50:    ++ optional withRuby_3_0 ruby_3_0
73:    ${optionalString withRuby_3_0   "./configure ruby   --module=ruby30   --ruby=${ruby_3_0}/bin/ruby"}

pkgs/applications/version-management/gitlab/default.nix
2:, ruby_3_0, tzdata, git, nettools, nixosTests, nodejs, openssl
20:    ruby = ruby_3_0;

pkgs/top-level/all-packages.nix
18230:    ruby_3_0
18239:  rubyPackages_3_0 = recurseIntoAttrs ruby_3_0.gems;

pkgs/top-level/pkg-config/pkg-config-data.json
778:        "ruby_3_0"

pkgs/development/interpreters/ruby/default.nix
337:  ruby_3_0 = generic {

pkgs/development/web/mailcatcher/default.nix
7:  ruby = pkgs.ruby_3_0;

In reply to @raitobezarius:matrix.org
hexa: i said to figsoda reserve the spot for the 2nd post