Posts tagged "compile times"

Measured with the same code as 1, 3 and 12 crates: splitting a Rust workspace narrows incremental rebuilds but increases total work, because generic instances are emitted once per crate.

Cargo can tell you exactly why it recompiled a crate. Here is the CARGO_LOG fingerprint command and six reproduced triggers, with the dirty reason each one prints.

A measured decision tree for slow Rust builds: use cargo --timings for the shape, the Cargo fingerprint log for unexpected rebuilds, and -Ztime-passes for the phase inside one crate.