`unresolved extern crate` for rustc private crates for 2025-03-17 nightly

[zjp-CN]

rust-analyzer version: rust-analyzer 1.87.0-nightly (43a2e9d 2025-03-17)

rustc version: rustc 1.87.0-nightly (43a2e9d 2025-03-17)

editor or extension: neovim

relevant settings:

• [package.metadata.rust-analyzer] rustc_private=true in Cargo.toml
• "rust-analyzer.rustc.source": "discover" in settings.json

code snippet to reproduce:

#![feature(rustc_private)]
extern crate stable_mir; // 👈 unresolved extern crate
fn main() {}

[toolchain]
channel = "nightly-2025-03-18" // change this to nightly-2025-04-01, the "unresolved extern crate" problem gone
components = ["llvm-tools", "rustc-dev", "rust-src", "rustfmt", "rust-analyzer"]

NOTE: I think this is likely a temporary regression in RA, because I've tested RA before or after 2025-03-17 version and found RA works well.

[Veykril]

Now the question is, is this a regression in r-a or did upstream change something regarding the compiler crate layout

[Veykril]

// change this to nightly-2025-04-01, the "unresolved extern crate" problem gone

Ah wait, so this is fixed in a newer rustup release?

[zjp-CN]

// change this to nightly-2025-04-01, the "unresolved extern crate" problem gone

Ah wait, so this is fixed in a newer rustup release?

Yes, I can confirm it.

[Veykril]

Given the last sync we did was march 3rd I believe that to have been caused by rust-lang/rust structure changes itself, given it works again there isn't really anything for us to do I believe