Stable Rustdoc contains broken links (to compiler internal crates)

[kumbayo]

The nightly rustdoc for Deref contains multiple links under Implementors which do not work.
https://doc.rust-lang.org/nightly/std/ops/trait.Deref.html
for example InternedString, RcSlice<T>, ThinVec<T>, P<T>, ...

Those links seem to come from internal crates like
rustc_data_structures, rustc_errors, syntax, syntax_pos

The problem does not appear for the stable documentation.
https://doc.rust-lang.org/stable/std/ops/trait.Deref.html

[Mark-Simulacrum]

I suspect that this may be due to an order change in how rustdoc builds things, or possibly a missing conditional around something. Unless something has landed into rustdoc itself recently that could cause this?

[QuietMisdreavus]

Looks like #43736 didn't fully solve this. There are some traits and types that are showing up without being in the implementors js file.

For example, f32 is shown to implement a trait from compiler_builtins:

And several types are showing up as implementors of Copy from crates like rand and libc:

While Float isn't showing up on stable right now, the rand and libc types are.

[shepmaster]

@jethrogb on #44175 states:

On the stable std::fmt::Debug page, under implementors, there's a bunch of links to the nightly documentation of the in-tree rand crate. What's more, the links don't work.

This first appeared in the 1.16 docs. Problem still exists in beta as of the 1.20 release candidate.

[QuietMisdreavus]

I have an open PR #44026 to address this, but i'm waiting for some confirmation from the dev-tools team to make sure i can merge it.