Compiler error missing from website error index

I am seeing the following error:

error[E0623]: lifetime mismatch
  --> src/book.rs:79:29
   |
57 | fn set_up_commodity_combo_box(commodity_editing: &CommodityEditing, globals: &Globals) {
   |                                                                              --------
   |                                                                              |
   |                                                                              these two types are declared with different lifetimes...
...
79 |                     *temp = Some(stmt);
   |                             ^^^^^^^^^^ ...but data from `globals` flows into `globals` here

But when I go to the compiler error index, https://doc.rust-lang.org/error-index.html, this error is not to be found. I assume it is the intention of the Rust developers that the error index document all errors the compiler currently produces. If so, what is the correct way to report this omission, aside from mentioning it here? (I am using the 1.39 compiler.)

I found the description at https://github.com/rust-lang/rust/blob/82cf3a4486bc882207a09bf0d9e2dea4632781aa/src/librustc_error_codes/error_codes/E0623.md

Thanks, that is helpful.

But the original issue remains: the omission from the easily-found index of compiler errors and how to report that omission.

I dont know why it is omitted, but you can report it at https://github.com/rust-lang/rust/issues.

I will. Thanks.