Include information about uncaught exceptions in user code (#3442)

Author: ZwFink

src/ck-core/init.C

@@ -1274,10 +1274,27 @@ void _sendReadonlies() {
 */
 void _initCharm(int unused_argc, char **argv)
 { 
-	int inCommThread = (CmiMyRank() == CmiMyNodeSize());
+  int inCommThread = (CmiMyRank() == CmiMyNodeSize());
 
-	DEBUGF(("[%d,%.6lf ] _initCharm started\n",CmiMyPe(),CmiWallTimer()));
-	std::set_terminate([](){ CkAbort("Unhandled C++ exception in user code.\n");});
+  DEBUGF(("[%d,%.6lf ] _initCharm started\n",CmiMyPe(),CmiWallTimer()));
+  std::set_terminate([](){
+    std::exception_ptr exptr = std::current_exception();
+    if (exptr)
+    {
+      try
+      {
+        std::rethrow_exception(exptr);
+      }
+      catch (std::exception &ex)
+      {
+        CkAbort("Unhandled C++ exception in user code: %s.\n", ex.what());
+      }
+    }
+    else
+    {
+      CkAbort("Unhandled C++ exception in user code.\n");
+    }
+  });
 
 	CkpvInitialize(size_t *, _offsets);
 	CkpvAccess(_offsets) = new size_t[32];