cannot truss jdk9 [ solaris ]

when attempting to truss a jvm ...

truss -f java Main

/2: mmap(0x00000000, 1048576, PROT_NONE, MAP_PRIVATE|MAP_NORESERVE, 3, 0) = 0xFFFFFFFF792C0000
/2: mmap(0xFFFFFFFF792C0000, 1048576, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED, 3, 0) = 0xFFFFFFFF792C0000
/2: openat(AT_FDCWD, "/proc/self/ctl", O_WRONLY)
Error: Could not find or load main class MainClass.java
        *** process otherwise traced, releasing ...

this appears to be caused by

bool os::enable_vtime() {
  int fd = ::open("/proc/self/ctl", O_WRONLY);
  if (fd == -1) {
    return false;
  }

  long cmd[] = { PCSET, PR_MSACCT };
  int res = ::write(fd, cmd, sizeof(long) * 2);
  ::close(fd);
  if (res != sizeof(long) * 2) {
    return false;
  }
  return true;
}

which is curious that since Solaris 10, PR_MSACCT is deprecated and no longer has any effect.

this causes a serious loss of observability in the JDK