diff --git a/src/mem/ruby/slicc_interface/AbstractController.cc b/src/mem/ruby/slicc_interface/AbstractController.cc
--- a/src/mem/ruby/slicc_interface/AbstractController.cc
+++ b/src/mem/ruby/slicc_interface/AbstractController.cc
@@ -26,8 +26,10 @@
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
+#include "mem/ruby/slicc_interface/AbstractController.hh"
+
+#include "debug/RubyQueue.hh"
 #include "mem/protocol/MemoryMsg.hh"
-#include "mem/ruby/slicc_interface/AbstractController.hh"
 #include "mem/ruby/system/Sequencer.hh"
 #include "mem/ruby/system/System.hh"
 #include "sim/system.hh"
@@ -104,6 +106,9 @@
         msgVec->resize(m_in_ports, NULL);
         m_waiting_buffers[addr] = msgVec;
     }
+    DPRINTF(RubyQueue, "stalling %s port %d addr %s\n", buf, m_cur_in_port,
+            addr);
+    assert(m_in_ports > m_cur_in_port);
     (*(m_waiting_buffers[addr]))[m_cur_in_port] = buf;
 }
 
# Node ID 8bb372e5bab1f8a9788f6540bcc9836ef9123775
# Parent  9c32bcb74db9845d3839c5e23d947875c5ed1b92
diff --git a/src/mem/ruby/network/MessageBuffer.cc b/src/mem/ruby/network/MessageBuffer.cc
--- a/src/mem/ruby/network/MessageBuffer.cc
+++ b/src/mem/ruby/network/MessageBuffer.cc
@@ -315,7 +315,7 @@
 void
 MessageBuffer::reanalyzeMessages(const Address& addr)
 {
-    DPRINTF(RubyQueue, "ReanalyzeMessages\n");
+    DPRINTF(RubyQueue, "ReanalyzeMessages %s\n", addr);
     assert(m_stall_msg_map.count(addr) > 0);
     Tick curTick = m_receiver->clockEdge();