Receiving RecursionError

Hi,

After upgrading to v.0.5.2 from v0.3.3, when I run the following command:
```python
forge.template("patient", output="json", only_required=True)
```

I receive the following error:
```python
_compile
RecursionError: maximum recursion depth exceeded while calling a Python object
```

It was successful in v0.3.3. Let me know if you need more details.

Just a note for tracking that I originally mentioned this problem in #132 although that issue was about another problem I was having.

The report names forge.template(...), _compile, and versions v0.3.3 and v0.5.2. Reproduce the command on both versions and capture a full traceback, then trace the _compile path to identify the regression; done means the command completes successfully with output="json" and only_required=True.

Written by the indexing model from the issue text.