rust-lang / rust-lang/rustc_codegen_cranelift

`cargo-clif build` slower than `cargo build`!

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Dominant language
Rust
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Description

I'm trying compile times on a medium size project and SURPRISE!

  • Windows 11, cargo 1.98.0 (797e8a9bc 2026-08-05):

cargo build: 1m 22s

  • Windows 11, cargo 1.100.0-nightly (e8cb624d5 2026-08-22) (cargo-clif @ 2bc05d4):

cargo-clif build: 1m 34s

cargo-clif build is slower than cargo build!

Of course I cargo clean before each command.

Instead the incremental build is different:

cargo build: 27s

cargo-clif build: 18s

Any idea?

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First steps

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Research direction

Start by reproducing the reported clean and incremental Windows 11 comparisons between cargo build and cargo-clif build using the versions and timings in the issue. Profile or otherwise compare the two build paths to identify why clean builds differ while incremental builds are faster. Done means the cause is understood and a measured improvement or documented explanation is available.

Written by the indexing model from the issue text.

Assessment

Tech stack
rust
Domain
compilers, performance
Issue type
Bug
Difficulty
4/5
Estimated time
3-5 days
Activity status
Active
Clarity
Needs clarification
Newbie friendliness
45/100

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