Rust allows overriding the default allocator with the #[global_allocator] attribute

struct MyAllocator;

unsafe impl GlobalAlloc for MyAllocator {
    unsafe fn alloc(&self, layout: Layout) -> *mut u8 {
        System.alloc(layout)
    }

    unsafe fn dealloc(&self, ptr: *mut u8, layout: Layout) {
        System.dealloc(ptr, layout)
    }
}

#[global_allocator]
static GLOBAL: MyAllocator = MyAllocator;

You could use this to change the behavior of the deallocation to your needs.

Or possably use an existing crate that impliment allocators tha logs the allocations/deallocations such as tracing-allocator or logging-allocator.

#[global_allocator]
static GLOBAL: tracing_allocator::Allocator = tracing_allocator::Allocator{};

fn main() {
  let f = File::create("trace.txt").unwrap();
  tracing_allocator::Allocator::initialize(&f);
  tracing_allocator::Allocator::activate();
}

(I have no experience with these crates so I have no idea what they uses for allocations)