diff --git a/lldb/tools/debugserver/source/MacOSX/MachProcess.mm b/lldb/tools/debugserver/source/MacOSX/MachProcess.mm
--- a/lldb/tools/debugserver/source/MacOSX/MachProcess.mm
+++ b/lldb/tools/debugserver/source/MacOSX/MachProcess.mm
@@ -2821,16 +2821,31 @@
           "attach to pid %d",
           getpid(), pid);
 
+      struct proc_bsdshortinfo proc;
+      int ppid = 0;
+      if (proc_pidinfo(pid, PROC_PIDT_SHORTBSDINFO, 0, &proc,
+                       PROC_PIDT_SHORTBSDINFO_SIZE) == sizeof(proc)) {
+        ppid = proc.pbsi_ppid;
+      }
       struct kinfo_proc kinfo;
       int mib[] = {CTL_KERN, KERN_PROC, KERN_PROC_PID, pid};
       size_t len = sizeof(struct kinfo_proc);
       if (sysctl(mib, sizeof(mib) / sizeof(mib[0]), &kinfo, &len, NULL, 0) == 0 && len > 0) {
         if (kinfo.kp_proc.p_flag & P_TRACED) {
-          ::snprintf(err_str, err_len, "%s - process %d is already being debugged", err.AsString(), pid);
-          DNBLogError(
-              "[LaunchAttach] (%d) MachProcess::AttachForDebug pid %d is "
-              "already being debugged",
-              getpid(), pid);
+          if (ppid != getpid()) {
+            snprintf(err_str, err_len,
+                     "%s - process %d is already being debugged by pid %d",
+                     err.AsString(), pid, ppid);
+            DNBLogError(
+                "[LaunchAttach] (%d) MachProcess::AttachForDebug pid %d is "
+                "already being debugged by pid %d",
+                getpid(), pid, ppid);
+          } else {
+            snprintf(err_str, err_len,
+                     "%s - Failed to attach to pid %d, AttachForDebug() "
+                     "unable to ptrace(PT_ATTACHEXC)",
+                     err.AsString(), m_pid);
+          }
         }
       }
     }
@@ -3401,7 +3416,13 @@
                                       "%d (err = %i, errno = %i (%s))",
                          m_pid, err, ptrace_err.Status(),
                          ptrace_err.AsString());
-        launch_err.SetError(NUB_GENERIC_ERROR, DNBError::Generic);
+        char err_msg[PATH_MAX];
+
+        snprintf(err_msg, sizeof(err_msg),
+                 "Failed to attach to pid %d, LaunchForDebug() unable to "
+                 "ptrace(PT_ATTACHEXC)",
+                 m_pid);
+        launch_err.SetErrorString(err_msg);
       }
     } else {
       launch_err.Clear();
@@ -3777,6 +3798,10 @@
       m_flags |= eMachProcessFlagsAttached;
       DNBLogThreadedIf(LOG_PROCESS, "successfully attached to pid %d", m_pid);
     } else {
+      launch_err.SetErrorString(
+          "Failed to attach to pid %d, SBLaunchForDebug() unable to "
+          "ptrace(PT_ATTACHEXC)",
+          m_pid);
       SetState(eStateExited);
       DNBLogThreadedIf(LOG_PROCESS, "error: failed to attach to pid %d", m_pid);
     }
@@ -3996,6 +4021,10 @@
       m_flags |= eMachProcessFlagsAttached;
       DNBLog("[LaunchAttach] successfully attached to pid %d", m_pid);
     } else {
+      launch_err.SetErrorString(
+          "Failed to attach to pid %d, BoardServiceLaunchForDebug() unable to "
+          "ptrace(PT_ATTACHEXC)",
+          m_pid);
       SetState(eStateExited);
       DNBLog("[LaunchAttach] END (%d) error: failed to attach to pid %d",
              getpid(), m_pid);
diff --git a/lldb/tools/debugserver/source/RNBRemote.cpp b/lldb/tools/debugserver/source/RNBRemote.cpp
--- a/lldb/tools/debugserver/source/RNBRemote.cpp
+++ b/lldb/tools/debugserver/source/RNBRemote.cpp
@@ -3636,10 +3636,23 @@
   if (sysctl(mib, sizeof(mib) / sizeof(mib[0]), &kinfo, &len, NULL, 0) != 0) {
     return false; // pid doesn't exist? well, it's not being debugged...
   }
-  if (kinfo.kp_proc.p_flag & P_TRACED)
-    return true; // is being debugged already
-  else
-    return false;
+  struct proc_bsdshortinfo proc;
+  int ppid = 0;
+  if (proc_pidinfo(pid, PROC_PIDT_SHORTBSDINFO, 0, &proc,
+                   PROC_PIDT_SHORTBSDINFO_SIZE) == sizeof(proc)) {
+    ppid = proc.pbsi_ppid;
+  }
+  if (kinfo.kp_proc.p_flag & P_TRACED) {
+    if (ppid != getpid()) {
+      return true; // is being debugged already
+    } else {
+      // being debugged, but by us. The attach
+      // failed for some reason after we had
+      // ptrace'd the process and become parent.
+      return false;
+    }
+  }
+  return false;
 }
 
 // Test if this current login session has a connection to the