# Buggy code
def __init__(self, hint=None, obj=None, name=None, exc=None):
    super(jinja2.Undefined, self).__init__()

    self.node = node
    self.name = name
    self.package_name = node.get("package_name")


# Traceback (RecursionError)
(MainThread): maximum recursion depth exceeded in comparison
2018-10-22 16:36:31,926 (MainThread): Traceback (most recent call last):
File "/Users/azme/anaconda3/lib/python3.6/site-packages/dbt/main.py", line 72, in main
results, succeeded = handle_and_check(args)
File "/Users/azme/anaconda3/lib/python3.6/site-packages/dbt/main.py", line 117, in handle_and_check
task, res = run_from_args(parsed)
File "/Users/azme/anaconda3/lib/python3.6/site-packages/dbt/main.py", line 172, in run_from_args
results = run_from_task(task, proj, parsed)
File "/Users/azme/anaconda3/lib/python3.6/site-packages/dbt/main.py", line 180, in run_from_task
result = task.run()
File "/Users/azme/anaconda3/lib/python3.6/site-packages/dbt/task/run.py", line 26, in run
results = runner.run(query, ModelRunner)
File "/Users/azme/anaconda3/lib/python3.6/site-packages/dbt/runner.py", line 244, in run
return self.run_from_graph(Selector, Runner, query)
File "/Users/azme/anaconda3/lib/python3.6/site-packages/dbt/runner.py", line 197, in run_from_graph
manifest, linker = self.compile(self.project)
File "/Users/azme/anaconda3/lib/python3.6/site-packages/dbt/runner.py", line 186, in compile
return compiler.compile()
File "/Users/azme/anaconda3/lib/python3.6/site-packages/dbt/compilation.py", line 241, in compile
manifest = dbt.loader.GraphLoader.load_all(self.project, all_projects)
File "/Users/azme/anaconda3/lib/python3.6/site-packages/dbt/loader.py", line 21, in load_all
nodes.update(loader.load_all(root_project, all_projects, macros))
File "/Users/azme/anaconda3/lib/python3.6/site-packages/dbt/loader.py", line 86, in load_all
macros)
File "/Users/azme/anaconda3/lib/python3.6/site-packages/dbt/loader.py", line 102, in load_project
macros=macros)
File "/Users/azme/anaconda3/lib/python3.6/site-packages/dbt/parser/base_sql.py", line 67, in load_and_parse
macros)
File "/Users/azme/anaconda3/lib/python3.6/site-packages/dbt/parser/base_sql.py", line 95, in parse_sql_nodes
macros=macros)
File "/Users/azme/anaconda3/lib/python3.6/site-packages/dbt/parser/base.py", line 125, in parse_node
schema_override = config.config.get('schema')
File "/Users/azme/anaconda3/lib/python3.6/site-packages/dbt/model.py", line 82, in config
self.in_model_config)
File "/Users/azme/anaconda3/lib/python3.6/site-packages/dbt/model.py", line 50, in _merge
merged_config.copy(), config.copy()
File "/Users/azme/anaconda3/lib/python3.6/site-packages/dbt/utils.py", line 251, in deep_merge
last = copy.deepcopy(lst.pop(len(lst)-1))
File "/Users/azme/anaconda3/lib/python3.6/copy.py", line 150, in deepcopy
y = copier(x, memo)
File "/Users/azme/anaconda3/lib/python3.6/copy.py", line 240, in _deepcopy_dict
y[deepcopy(key, memo)] = deepcopy(value, memo)
File "/Users/azme/anaconda3/lib/python3.6/copy.py", line 180, in deepcopy
y = _reconstruct(x, memo, *rv)
File "/Users/azme/anaconda3/lib/python3.6/copy.py", line 281, in _reconstruct
if hasattr(y, '__setstate__'):
File "/Users/azme/anaconda3/lib/python3.6/site-packages/dbt/clients/jinja.py", line 165, in __getattr__
self.package_name = self.name
File "/Users/azme/anaconda3/lib/python3.6/site-packages/dbt/clients/jinja.py", line 165, in __getattr__
self.package_name = self.name
File "/Users/azme/anaconda3/lib/python3.6/site-packages/dbt/clients/jinja.py", line 165, in __getattr__
self.package_name = self.name
[Previous line repeated 320 more times]
File "/Users/azme/anaconda3/lib/python3.6/site-packages/dbt/clients/jinja.py", line 162, in __getattr__
if name in ['unsafe_callable', 'alters_data']:
RecursionError: maximum recursion depth exceeded in comparison

# Fixed code
def __init__(self, hint=None, obj=None, name=None, exc=None):
    super(jinja2.Undefined, self).__init__()
    self.node = node
    self.name = name
    self.package_name = node.get("package_name")
    # jinja uses these for safety, so we have to override them.
    # see https://github.com/pallets/jinja/blob/master/jinja2/sandbox.py#L332-L339 # noqa
    self.unsafe_callable = False
    self.alters_data = False