Compile times have increased dramatically, impacting iterative coding and debugging.

Every time I modify Rust linter code and run it again to see if I got it right, takes at least twice as long as it did recently.

Start by reproducing the reported compile-time increase after modifying the Rust linter code, then compare the current timing with the recent baseline described in the issue. The issue does not name files, tests, or an entry point; done means identifying and addressing the regression so iterative compilation no longer takes at least twice as long.

Written by the indexing model from the issue text.