There are packages that depend on app-admin/sudo. Most of its use is trivial (as in `sudo command-to-call`) and can be replaced with app-admin/doas or something else. Currently, a user needs to add "app-admin/sudo-9999" to package.provided and create a symlink manually. I don't know if it's a good idea to add "app-alternatives/sudo" since command-line flags are not compatible. What do you think?
They're not compatible, indeed. Assuming that it's off the table to symlink not-sudo programs to /usr/bin/sudo, a package such as "app-alternatives/root-elevation-helper" might be more apropos. It wouldn't even be limited to sudo and doas, you can do the same thing with polkit via `pkexec`. The big problem is that you'd need to invent your own standard for a generic command. Debian does something similar with e.g. `editor` (and `sensible-editor`). Then you'd also need to edit every package that runs sudo, to run the wrapper thing instead (after making sure it doesn't use options incompatible with any providers). I wouldn't really consider this worth it. There aren't very many packages that use this to begin with, and personally I'm a bit suspicious of even that.
Closing per above. I don't think we can do this. You may want a virtual or something where packages genuinely want trivial 'sudo' use.