parse_arguments is safe. It takes arguments: *const AnyObject and argc, and calls slice::from_raw_parts(arguments, argc as usize).
It does not check that arguments is non-null and aligned, or that argc elements are initialized. Safe Rust can pass a null pointer or a length past the allocation. The maintainer confirmed this on 2026-10-03, including a debug abort on Rust 1.78+ when Ruby calls an arity -1 method (to_s via format, puts, or Array#join) with a NULL argv and argc of 0.
{
"license": "CC0-1.0"
}