kill -USR2 apparently not working

Hey All,

I'm running on Ubuntu 12.04 and nginx 1.5.12 compiled from source. I'm attempting to upgrade nginx to 1.6.0 on my production servers without incurring any downtime. Ideally, I'd like to:

1) Replace the binary
2) send the master PID a kill -USR2 (kill -USR2 `cat /usr/local/nginx/logs/nginx.pid`)
3) WINCH the old master PID (kill -WINCH `cat /usr/local/nginx/logs/nginx.pid.oldbin`)

Recompiling from source works great. However, when I send the USR2 to the current master PID nothing seems to happen. The process list (`ps aux | grep nginx | grep -v grep`) does not change at all; I would expect to see a new master PID. I am also not seeing a nginx.pid.oldbin file in /usr/local/nginx/logs. I've tried sending both a USR2 and INT (even though they are apparently the same signal). I don't believe `kill` has verbose output or any way to tell me what is actually happening when I send the signal. My next step is to attach to the process with strace to see what syscalls get made when I send USR2 but am not entirely sure how far that will really get me.

I've posted this question in the IRC channel to no avail thus far, so hopefully someone on the forums will be able to assist!

Thanks for reading!

Jaryd