+#else
+ // Solaris' DTrace can't handle the
+ // __dtrace_isenabled$HaskellEvent$user__msg$v1
+ // call above. This call is just for testing whether the user__msg
+ // probe is enabled, and is here for just performance optimization.
+ // Since preparation for the probe is not that complex I disable usage of
+ // this test above for Solaris and enable the probe usage manually
+ // here. Please note that this does not mean that the probe will be
+ // used during the runtime! You still need to enable it by consumption
+ // in your dtrace script as you do with any other probe.
+ enabled = 1;
+#endif