Explicitly set the pValue pointer to NULL.

PyTuple_SetItem “steals” a reference to pValue, but
does not set it to NULL after dereferencing it. It
causes segmentation fault when running lammps on some
systems and on multiple processors since it is trying
to decrement the reference count for an object which
does not exist.

src/KIM/kim_property.cpp

@@ -464,7 +464,8 @@ void kimProperty::command(int narg, char **arg)
         error->one(FLERR, "Error Python `kim_property_dump` function "
                           "evaluation failed!");
       }
-    }
+    } else
+      pValue = NULL;
 
     // Destroy the variable
     kim_str_cmd[1] = const_cast<char *>("delete");