Dear Maintainer,

fatrace is suddenly pretty noisy with (spurious?) error messages of the
form "failed to open /proc/XXXXXX: No such file or directory". In a few
instances it also attempts accessing the /comm subdirectory. So when not
redirecting stderr, even on a rather short run and relatively silent
system, I'm easily seeing hundreds of such lines. Of course, these don't
end up in the regular output file, though I don't think it's intended
behavior and there is hardly a point. My guess is these are simply due
to very short-lived processes, like there's some kind race condition.
It's apparently harmless, but if so might better be ignored.

Regards,
Oliver

Hello Oliver,

Oliver M. Schode [2025-11-19  0:27 +0100]:

This wasn't actually an accident, but a conscious decision -- albeit I'm not at
all sure about it. These errors explain why you get incomplete information,
such as "unknown" process names. On the other hand they are not really
actionable and noisy.

This bug report is the first piece of feedback that I get about this. I'm ok
with dimming them down to debug messages again.

The real fix would be to have a Linux API that isn't racy -- fanotify is really
broken for short-lived processes unfortunately. I guess the solution will have
"EBPF" in the name, but there you can't collect process information either 😢

Martin