Constant SYSROOT_INTERNAL 

const SYSROOT_INTERNAL: &str = "__CARGO_FIX_RUST_SRC";

Internal only. The sysroot path.

This is for preventing cargo fix from fixing rust std/core libs. See

• https://github.com/rust-lang/cargo/issues/9857
• https://github.com/rust-lang/rust/issues/88514#issuecomment-2043469384