We are migrating packages that meet below requirements:
1. using `callPackage`
2. called path is a directory
3. overriding set is empty (`{ }`)
4. not containing path expressions other than relative path (to
makenixpkgs-vet happy)
5. not referenced by nix files outside of the directory, other
than`pkgs/top-level/all-packages.nix`
6. not referencing nix files outside of the directory
7. not referencing `default.nix` (since it's changed to `package.nix`)
8. `outPath` doesn't change after migration
The tool is here: https://github.com/Aleksanaa/by-name-migrate.
- new Boolean selectors:
- useSystemFfmpeg, default false
- because PPSSPP project uses a heavily patched fork of ffmpeg_4
- useSystemSnappy, default true
- move wrapping to postFixup
- unpin ffmpeg_4 and glew
- it required a self-referent argset
Phew!
