It isn't disabled, it has exclusions. Now that they have it, they can close the gaps. It was literally impossible to have ANY coverage before, now they are mostly, covered and have an avenue for remediation.

I don't understand why folk are having such a hard time understanding why you do large projects in multiple steps? 80/20 rule? Perfect is the enemy of good?

Was nobody here for moving billions of lines of JavaScript to Typescript? It starts with declarations, then turn on type checking gradually inside the codebase: piece by piece until done.

I like Rust and use it full-time professionally. Unsafe is not the same as unsound. Unsound means that the unsafe code is not maintaining the aliasing invariants on references required by the language, and thus undefined behavior can leak into safe code (that is, the safe code can be miscompiled).

Known unsound code should not be merged, let alone released to production. If you have good enough tests and run them under MIRI or ASAN, maybe you can get away with it for a time, but most Rust experts would not sign-off on such a project.

If somebody put a gun to my head and told me to make the best of such a codebase, I would try to figure out how to turn off the LLVM optimizations that assume the Rust references don't alias. With these optimizations this codebase is scarier than most C or C++ code.