Download the executable? That's not safe. Even if your intentions are good, you're teaching bad security habits.

"That bug was a real head-scratcher for me. I'm glad I figured it out. The simple fix is to pipe stderr to /dev/null. "

That's kind of a nope. It's a feature, not a bug. FFMPEG will exit with 0 even on an actual error for what you were expecting. In one of TFA examples using -ss 5 -to 10, you're expecting a result of a 5 second clip. If for some reason, there was an issue reading the file at 8 seconds, ffmpeg will exit with 0 and an output that was only 3 seconds long. If you dumped stderr to /dev/null, you'd have no idea why.

FFMPEG definitely does some weird things with stdout/stderr for people that are new to it. However, there are reasons for its behavior that make sense after long enough use of it. Being able to pipe raw video using stdout instead of forcing a dump to a file is full on Matrix level flex that distorts the surrounding environment. So if the actual video is going out stdout, stderr receives all of the other info that normies would expect to see on stdout. This is why so many people use 2>/path/to/log so that at the end of the process with an exit 0 any issues with an output can be ascertained.