`clippy::todo`

Replace todo! with the intended implementation or remove the reachable placeholder.

What it reads

Clippy, with the compiler behind it. The only pass that compiles.

Ordinary defect.

The tier bounds how severe a rule may be; its category bounds the tier.

Turn it off, or make it blocking, without touching the code it flags:

rust-doctor --rule clippy::todo=off .
rust-doctor --rule clippy::todo=error .