No RA diagnostics in Miri or other rustc_private-using projects

[RalfJung]

As mentioned here and confirmed by @Veykril, something is preventing any RA diagnostic from showing up in Miri. I'd expect a bunch of errors due to #13504, but also if I introduce an error artificially (like a trivially wrong argument), I don't get any diagnostics.

User settings:

    "rust-analyzer.lens.enable": false,
    "rust-analyzer.cachePriming.enable": false,
    "rust-analyzer.cargo.buildScripts.useRustcWrapper": false, // https://github.com/rust-lang/rust-analyzer/issues/14722
    "rust-analyzer.diagnostics.disabled": [
        "unlinked-file",
    ],

Project settings:

{
    "rust-analyzer.rustc.source": "discover",
    "rust-analyzer.linkedProjects": [
        "Cargo.toml",
        "cargo-miri/Cargo.toml",
        "miri-script/Cargo.toml",
    ],
    "rust-analyzer.check.invocationStrategy": "once",
    "rust-analyzer.check.overrideCommand": [
        "./miri",
        "clippy",
        "--all-features",
        "--message-format=json",
    ],
    "rust-analyzer.cargo.features": "all",
    "rust-analyzer.cargo.extraEnv": {
        "MIRI_AUTO_OPS": "no",
        "MIRI_IN_RA": "1",
    },
    // Contrary to what the name suggests, this also affects proc macros.
    "rust-analyzer.cargo.buildScripts.invocationStrategy": "once",
    "rust-analyzer.cargo.buildScripts.overrideCommand": [
        "./miri",
        "check",
        "--all-features",
        "-Zunstable-options",
        "--compile-time-deps",
        "--message-format=json",
    ],
}

[RalfJung]

I have another project with rustc_private dependencies and I don't get diagnostics there either. Ctrl-click works, the tooltips show the right types, everything indicates that RA understands the code -- but there's no diagnostics when I do something silly like passing None for a non-Option argument.

This applies even to code that's entirely local and has no rustc_private involvement. E.g. if I take the following snippet

fn ratest(x: i32) {
    ratest(None)
}

and I paste it in a normal project, RA immediately complains before I even hit Ctrl-S to trigger check-on-save. But in both of my rustc_private projects, nothing happens.

[ChayimFriedman2]

Perhaps you have disabled r-a diagnostics globally?

[RalfJung]

As I said, it works in other projects, just not the ones that use rustc_private. So they are clearly not globally disabled. I have pasted my local (Miri) and global settings above. For the non-miri rustc_private project, the local settings are

{
    "rust-analyzer.rustc.source": "discover",
    "rust-analyzer.linkedProjects": [
        "./tooling/minimize/Cargo.toml",
    ],
}

[RalfJung]

Argh I must have fat-fingered "tab - enter" somehow and then GH closed the issue... could someone reopen please? :)

[Veykril]

you can't re-open your own? 🤔

[RalfJung]

Nope 🤷

[ChayimFriedman2]

I think I've spotted the cause for this. Here:

rust-analyzer/crates/rust-analyzer/src/handlers/dispatch.rs

Line 144 in 0ee81de

if !self.global_state.vfs_done || self.global_state.incomplete_crate_graph {

incomplete_crate_graph is true forever, due to some file missing from the VFS for some reason. The file is `~/.rustup/toolchains/../lib/rustlib/rustc-src/rust/library/proc_macro/src/lib.rs, and once I force it into the VFS by opening it in the editor diagnostics work. So, something fishy is going on.

[RalfJung]

Oh wow indeed, I can reproduce that. When I open that file (/home/r/.rustup/toolchains/miri/lib/rustlib/rustc-src/rust/library/proc_macro/src/lib.rs), some processing happens (messages flash through the status bar), and a few seconds later RA diagnostics start showing up.