Recommitting r180831 with trivial fix - remember to return errors if you compute.

llvm-svn: 180898
diff --git a/lldb/source/Plugins/Process/POSIX/ProcessPOSIX.cpp b/lldb/source/Plugins/Process/POSIX/ProcessPOSIX.cpp
index 137fa46..35c365f 100644
--- a/lldb/source/Plugins/Process/POSIX/ProcessPOSIX.cpp
+++ b/lldb/source/Plugins/Process/POSIX/ProcessPOSIX.cpp
@@ -283,9 +283,16 @@
 }
 
 Error
-ProcessPOSIX::DoDetach()
+ProcessPOSIX::DoDetach(bool keep_stopped)
 {
     Error error;
+    if (keep_stopped)
+    {
+        // FIXME: If you want to implement keep_stopped on Linux,
+        // this would be the place to do it.
+        error.SetErrorString("Detaching with keep_stopped true is not currently supported on Linux.");
+        return error;
+    }
 
     error = m_monitor->Detach();
     if (error.Success())