truss kills process?

[Mateusz Kwiatkowski]

Hello, 

We noticed quite strange behaviour of truss:

# sleep 100 &
[1] 93212
# truss -p 93212
sigprocmask(SIG_BLOCK,SIGHUP|SIGINT|SIGQUIT|SIGKILL|SIGPIPE|SIGALRM|SIGTERM|SIGURG|SIGSTOP|SIGTSTP|SIGCONT|SIGCHLD|SIGTTIN|SIGTTOU|SIGIO|SIGXCPU|SIGXFSZ|SIGVTALRM|SIGPROF|SIGWINCH|SIGINFO|SIGUSR1|SIGUSR2,0x0)
= 0 (0x0) sigprocmask(SIG_SETMASK,0x0,0x0)                 = 0 (0x0)
sigprocmask(SIG_BLOCK,SIGHUP|SIGINT|SIGQUIT|SIGKILL|SIGPIPE|SIGALRM|SIGTERM|SIGURG|SIGSTOP|SIGTSTP|SIGCONT|SIGCHLD|SIGTTIN|SIGTTOU|SIGIO|SIGXCPU|SIGXFSZ|SIGVTALRM|SIGPROF|SIGWINCH|SIGINFO|SIGUSR1|SIGUSR2,0x0)
= 0 (0x0) sigprocmask(SIG_SETMASK,0x0,0x0)                 = 0 (0x0)
process exit, rval = 0
[1]  + done       sleep 100

Sleep ends immediately instead of waiting for desired number of seconds.
I wonder if this is normal behavior or maybe a bug?
Checked under 8.2-RELEASE-p3 and 9.0-RELEASE.

-- 
Mateusz Kwiatkowski