Reproducer (using indicatif 0.17.8, default feature set):

use indicatif::{ProgressBar, ProgressStyle};

fn main() {
    let pb_style = ProgressStyle::default_bar()
        .template("{bar:16} | {pos:>6}/{len:6} | {per_sec:>8}")
        .unwrap();

    let pb = ProgressBar::new(100000).with_style(pb_style);

    for _ in 0..1000 {
        std::thread::sleep(std::time::Duration::from_secs_f64(0.01));
        pb.inc(100);
    }
    pb.finish();
}

The progress bar that's left after the program runs:

████████████████ | 100000/100000 | 9,631.6687/s

Despite per_sec specifying a width of 8 characters, the final per_sec display is 12 characters wide. I would have expected the formatter to trim the number of digits after the decimal point to reduce the width instead.

Compressed asciinema recording of the above program running on my machine:

pb_per_sec.cast.gz