title: DTrace error in macOS Sierra
body: <p>I was trying to use a <code>dtrace</code> command in my macOS Sierra to profile a node.js application like this:</p>
  
  <p><code>sudo dtrace -x ustackframes=100 -n 'profile-97 /pid == 35526/ { @[ustack()] = count(); } tick-60s { exit(0); }' -o out.user_stacks</code> </p>
  
  <p>and that's erroring out like this:</p>
  
  <pre><code>dtrace: description 'profile-97 ' matched 2 probes
  dtrace: error on enabled probe ID 1 (ID 37: profile:::profile-97): invalid address (0x405060700010203) in action #2
  dtrace: error on enabled probe ID 1 (ID 37: profile:::profile-97): invalid address (0x405060700010203) in action #2
  dtrace: error on enabled probe ID 1 (ID 37: profile:::profile-97): invalid address (0x6eac0bf) in action #2
  </code></pre>
  
  <p>I have googled and found this : <a href="https://unix.stackexchange.com/questions/275175/error-on-enabled-probe-syscallopen-nocancelentry-invalid-user-access-in-ac">https://unix.stackexchange.com/questions/275175/error-on-enabled-probe-syscallopen-nocancelentry-invalid-user-access-in-ac</a></p>
  
  <p>but read that doing that is not safe. Can someone please explain what that error means and why it's caused? If I see errors like this, will dtrace produce correct <code>stack traces</code>?</p>
  
  <p>How can I resolve this errors? Thanks</p>