bash: !someActualEvent: event not found

Don't you hate errors like this?

$ strace -etrace=!futex -p 3181
bash: !futex: event not found

If this happens to you do not worry. Just escape the bang (!) like this:

$ strace -etrace=\!futex -p 3181
Process 3181 attached - interrupt to quit

The strace man page is wrong for bash. Imagine that.

Hope that helps.