Debug output doesn't honor formatting specifier x

[chkno]

use num_bigint::BigUint;
 
fn main() {
    let small = 32768usize;
    let big = BigUint::from(small);
    println!("{small:x} {big:x}");
    println!("{small:x?} {big:x?}");
}

Prints:

8000 8000
8000 32768

It should print:

8000 8000
8000 8000

[cuviper]

There's no public way for us to get that flag from the Formatter:
rust-lang/rust#48584