#5284 happened, so instead I'll open a proper issue to address what I feel would be the "correct" solution since I am incapable of implementing it atm.

I see no particular reason why self should be especially handicapped from the other inputs, but should be able to be easily handled as a regular git type input, or whichever active VCS Nix can detect.

you wouldn't even have to change the syntax, but simply allow inputs.self.submodules = true, for example.

Nix would simply have to know that inputs.self is the current self.