Upgrading 2020-09-14 -> 2020-09-21 broke #![feature(rustc_private)]

[khyperia]

Setup

Cargo.toml:

[package]
name = "nightlytest"
version = "0.1.0"
authors = ["khyperia <github@khyperia.com>"]
edition = "2018"

[lib]
crate-type = ["dylib"]

[dependencies]

rust-toolchain:

nightly

src/lib.rs:

#![feature(rustc_private)]

extern crate rustc_ast;

Expected behavior, behavior on rust-analyzer 2020-09-14

No error

Actual behavior on rust-analyzer 2020-09-21

Red squiggles on the extern crate, with popup unresolved extern crate. cargo build etc. still works fine.

[kiljacken]

Just for context: I don't believe it's as much us breaking rustc_private, but introducing a diagnostic for unresolved imports in rust-analyzer instead of depending on cargo check. So this is very likely #6016.

You should be able to silence the diagnostic by adding the following to your vscode config:

"rust-analyzer.diagnostics.disabled": ["unresolved-extern-crate"]

[khyperia]

Aah gotcha, thanks, that is indeed what's happening (diagnostics for things in rustc crates still work, e.g. use rustc_ast::asdf errors but use rustc_ast::[valid item] doesn't), sorry for the silly bug report! Should have investigated a little bit more and figured that out.

[kiljacken]

No worries! Rather an extraneous bug report than a missed issue :)

EDIT: Also, the false positive should go away once #3517 is fixed, which seemed to have just been unblocked by an upstream update.