samply: Command-line sampling profiler for macOS, Linux, and Windows

It's amazing how samply "just works", at least on macOS. You can take any binary call, prefix it with `sample record --` and you'll get a flamegraph (and more) in the nice Firefox profiler UI.

I had trouble finding a good profiler for my Rust program on macOS, samply was love at first sight around 3 years ago. It's only gotten better since AFAICT.

The author Markus Stange apparently works at Mozilla on the Performance team.