Weihang Lo

I feel like it is a niche use case, and a bit error-prone to implement this, since the acquisition of package cache lock occurs in multiple different places. It's also...

Away from keyboard right now. Could you help check whether `-Zrustdoc-depinfo` fixed it? https://doc.rust-lang.org/cargo/reference/unstable.html#rustdoc-depinfo

Cargo compares output file's mtime (`target/doc/dep.json`) with all its dependency outputs mtime to determine whether it needs to rebuild (see this [`check_filesystem()`](https://github.com/rust-lang/cargo/blob/b5354b56860cd74469be873eb06220a4a5137c99/src/cargo/core/compiler/fingerprint/mod.rs?plain=1#L1181-L1316)). It is not an issue for `cargo check`...

> Alternatively we could resolve this in rustdoc, by fixing [rust-lang/rust#142370](https://github.com/rust-lang/rust/issues/142370). > This would involve rustdoc adding the value of `-Cmetadata` or `-Cextra-filename`. > I think this is preferable because...

Let me add this as blocked-external, since t-cargo and t-rustdoc need to agree on some designs here. @rustbot label +S-blocked-external -S-triage +A-rebuild-detection

See [#t-cargo > rustdoc-json output filename design](https://rust-lang.zulipchat.com/#narrow/channel/246057-t-cargo/topic/rustdoc-json.20output.20filename.20design/with/560014414). Cargo might need to change `--out-dir` to something location like `target/path/to/private/location/foo-12ab34ef/foo.json`, and uplift to `target/doc/foo.json`. * We need to make sure that `--message-format=json`...

To me, if not going to build with LTO, I would just not set any flag for that. Also, `lto` is usually determined on a package basis. If you really...

Cargo leverages , as we want path on file system as stable as possible, regardless endianness or platform. Tha said, not everything in this codebase has this requirement There are...

I wonder how bad it was in terms of total run time of the clippy command being benchmarked.

cc @NobodyXu you might be interested.