Easier solution: you don’t need a progress bar.

Depends on the purpose… but I guess if you replace it with estimated time left, may be good enough. Sometimes progress bar is just there to identify whether you need stop the job since it takes too much time.

It runs indefinitely to process small jobs. I could log stats somewhere, but it complicates things. Right now, it's just a single binary that automatically gets restarted in case of a problem.

One of the wisest comments I've ever seen on HN.

Every feature is also a potential vulnerability.

And if you really do? Print the percentage to stdout.