rust-analyser hangs at "Fetching", and uses CPU at 100%

[lmsonic]

rust-analyzer version: 0.3.1850 (latest at time of writing)

rustc version: rustc 1.78.0-nightly (3246e7951 2024-02-19)

System specs:
Windows 10
Processor 11th Gen Intel(R) Core(TM) i7-11800H @ 2.30GHz 2.30 GHz
Installed RAM 16,0 GB (15,8 GB usable)
System type 64-bit operating system, x64-based processor

relevant settings:
Project is a bevy project setup as in this link https://bevyengine.org/learn/quick-start/getting-started/setup/ (I am using VSCode)

# Cargo.toml

[dependencies]
bevy = { version = "0.12.0", features = ["dynamic_linking"] }

# Enable a small amount of optimization in debug mode
[profile.dev]
opt-level = 1

# Enable high optimizations for dependencies (incl. Bevy), but not for our code:
[profile.dev.package."*"]
opt-level = 3

# .cargo/config.toml
[target.x86_64-pc-windows-msvc]
linker = "rust-lld.exe" # Use LLD Linker
rustflags = [
    "-Zshare-generics=n",
    "-Zthreads=0",        # (Nightly) Use improved multithreading with the recommended amount of threads.
]

# Optional: Uncommenting the following improves compile times, but reduces the amount of debug info to 'line number tables only'
# In most cases the gains are negligible, but if you are on macos and have slow compile times you should see significant gains.
[profile.dev]
debug = 1

# Rust analyser settings in vscode
    "rust-analyzer.server.extraEnv": {
        "CARGO_TARGET_DIR": "target/analyzer",
    },
    "rust-analyzer.check.extraArgs": [
        "--target-dir=target/analyzer"
    ],
    "rust-analyzer.cargo.extraEnv": {
        "CARGO_PROFILE_RUST_ANALYZER_INHERITS": "dev",
        "RUSTFLAGS": "-Clinker=rust-lld.exe"
    },
    "rust-analyzer.cargo.extraArgs": [
        "--profile",
        "rust-analyzer"
    ],
    "rust-analyzer.check.overrideCommand": [
        "cargo",
        "clippy",
        "--workspace",
        "--message-format=json",
        "--all-targets",
    ],

Like in the title, rust-analyser hangs at "Fetching" when starting the project, if I click on show logs it doesn't show anything, but it keeps using the CPU with multiple rustc processes at 100%. I tried cleaning up the cache, reinstalling rust, messing with num thread and cache priming settings, but nothing worked.

The only thing that worked to make it usable was to revert to v0.3.1839, and now everything works fine. I will stay on that for now until it gets fixed :)

[qoheniac]

Another workaround is to use the pre-release version 0.4.1851

[iNeXcf]

For me pre-release version 0.4.1851 and version 0.3.1850 show the same behavior. v0.3.1839 is working correctly.

[Veykril]

This seems to be non-deterministic ...

[freezdream]

Also affected. Fetching eventually finishes, but it easily takes half an hour. Afterwards it is responsive until I run a build on the command line (which, after rust-analyzer ran requires rebuilding half the application starting from proc_macro2, even if there were no changes).
So it seems like rust-analzer invalidates regular builds and vice versa.

Reverting back to 0.3.1839 fixed the issue for me as well.

[Veykril]

Most likely caused by #16537 / #16563, I only ran into it once earlier but I can't seem to reproduce it now.

[Veykril]

Actually it could beis #16247

[Veykril]

For the time being you can disable rust-analyzer.cargo.buildScripts.rebuildOnSave, that should avoid the issue until a fix is landed I think.

[Veykril]

#16616 should fix this I believe, I pushed out a new nightly release if some of you could check with the rust-analyzer.cargo.buildScripts.rebuildOnSave enabled again on that release that would be great