[dataformat] Add more information to type method error if not resolved

beat/backend/python/dataformat.py

@@ -317,7 +317,11 @@ class DataFormat(object):
         """
 
         if self.resolved is None:
-            raise RuntimeError("Cannot prototype while not properly initialized")
+            raise RuntimeError(
+                "Cannot prototype while not properly initialized\n{}".format(
+                    self.errors
+                )
+            )
 
         classname = re.sub(r"[-/]", "_", self.name)
         if not isinstance(classname, str):