Here's my current plan to implement part 2 of RFC 140:

0. Implement a strategy to make it easy to increase the strictness of the pkgs/by-name CI check:
   • A strategy for evolving the pkgs/by-name CI checks #256788
   • tests.nixpkgs-check-by-name: Implement gradual empty arg check migration #272395
1. Require packages that use pkgs/by-name to not be defined with an { } argument in all-packages.nix:
   • Implement check to disallow pkgs/by-name package definitions in all-packages.nix with an empty argument #256792
   • tests.nixpkgs-check-by-name: Implement gradual empty arg check migration #272395
   • pkgs/by-name: Enable gradual migration checks and add run-local.sh #274591
2. Require new packages using callPackage to use pkgs/by-name
   • check-by-name: Refactor to prepare for enforcing pkgs/by-name, make --base required #278805
   • [RFC 140 2a] pkgs/by-name: Enforce for new packages #275539
3. Try to migrate all packages that don't cause failures or output path changes
   • treewide: migrate packages to pkgs/by-name, take 1 #354531
   • still left to do:
     • defined in individual files
     • with override (callPackage ./foo.nix { foo = bar; })

Ping the Nixpkgs Architecture Team, @roberth @Ericson2314 @tomberek @aakropotkin @DavHau @phaer