This is not a patch ready for inclusion yet, but rather to get the ball rolling on some changes to ptrace.
Once the patch is cleaned up I'd like to see it pulled in.
Discussion: strace doesn't always run right now because it hangs up on lack of SEIZE support. SEIZE is like ATTACH, but it doesn't leave the process stopped after attaching. Rather a follow up INTERRUPT is issued to actually stop the process and wait for events.
Unlike ATTACH, in SEIZE we immediately get ptrace options and can set them right away.
With this patch, strace reliably runs on my end whereas the previous effect was a 'nothing happening' strace.