CACHEDIR.TAG not created if rust-analyzer runs before cargo build

[problame]

Problem

After checking out a Rust/Cargo project from Git, if rust-analyzer is run before the first cargo build, the target/CACHEDIR.TAG is missing

Steps

1. Check out some default Rust/Cargo project that has target directory excluded from Git.
2. Open in a VSCode code . that has rust-analyzer extension installed
3. Wait a bit until target/analyzer/CACHEDIR.TAG is created
4. cargo build => cargo build not creating target/CACHEDIR.TAG

Possible Solution(s)

Revert https://github.com/rust-lang/cargo/pull/13132/files

Notes

I verified that this reproduces on both macOS and Linux.

Version

cargo 1.79.0 (ffa9cf99a 2024-06-03)
release: 1.79.0
commit-hash: ffa9cf99a594e59032757403d4c780b46dc2c43a
commit-date: 2024-06-03
host: aarch64-unknown-linux-gnu
libgit2: 1.7.2 (sys:0.18.3 vendored)
libcurl: 8.6.0-DEV (sys:0.4.72+curl-8.6.0 vendored ssl:OpenSSL/1.1.1w)
ssl: OpenSSL 1.1.1w  11 Sep 2023
os: Debian 11.0.0 (bullseye) [64-bit]

[weihanglo]

Where did you configure target/analyzer/CACHEDIR.TAG?
The directory doesn't seem to be created when trying to reproduce it with Rust Analyzer v0.3.2037.

Could you give a complete reproducer like

• Which repo you cloned and run
• The version of the rust-analyzer extension

[weihanglo]

Relevant issues:

• CACHEDIR.TAG is not created if the target already exists #12441

[problame]

Where did you configure target/analyzer/CACHEDIR.TAG?

Hm, I configured target/analyzer in vscode

...
    "rust-analyzer.server.extraEnv": {
        "CARGO_TARGET_DIR": "target/analyzer"
    },
    "rust-analyzer.check.extraArgs": [
        "--target-dir=target/analyzer"
    ],
...

(Snippet from here: rust-lang/rust-analyzer#6007 (comment) )

So, I guess we can dedupe this into #12441

[weihanglo]

Yeah that seems like a dup. I am going to close this.
Would you mind sharing ideas in #12441 about why CACHEDIR.TAG is critical in this case, and why a separate target dir is needed? We can discuss there.