pfb_fhir config without a config creates a stack trace.

[bwalsh]

$ pfb_fhir config
Traceback (most recent call last):
File "/Users/walsbr/aced/data_model/venv/bin/pfb_fhir", line 8, in
sys.exit(cli())
File "/Users/walsbr/aced/data_model/venv/lib/python3.9/site-packages/click/core.py", line 829, in call
return self.main(*args, **kwargs)
File "/Users/walsbr/aced/data_model/venv/lib/python3.9/site-packages/click/core.py", line 782, in main
rv = self.invoke(ctx)
File "/Users/walsbr/aced/data_model/venv/lib/python3.9/site-packages/click/core.py", line 1259, in invoke
return _process_result(sub_ctx.command.invoke(sub_ctx))
File "/Users/walsbr/aced/data_model/venv/lib/python3.9/site-packages/click/core.py", line 1066, in invoke
return ctx.invoke(self.callback, **ctx.params)
File "/Users/walsbr/aced/data_model/venv/lib/python3.9/site-packages/click/core.py", line 610, in invoke
return callback(*args, **kwargs)
File "/Users/walsbr/aced/data_model/venv/lib/python3.9/site-packages/click/decorators.py", line 21, in new_func
return f(get_current_context(), *args, **kwargs)
File "/Users/walsbr/aced/data_model/venv/lib/python3.9/site-packages/pfb_fhir/cli.py", line 213, in config
print(ctx.obj['model'].json())

[bwalsh]

Also

$ pfb_fhir config --format yaml
Traceback (most recent call last):
File "/Users/walsbr/aced/data_model/venv/bin/pfb_fhir", line 8, in
sys.exit(cli())
File "/Users/walsbr/aced/data_model/venv/lib/python3.9/site-packages/click/core.py", line 829, in call
return self.main(*args, **kwargs)
File "/Users/walsbr/aced/data_model/venv/lib/python3.9/site-packages/click/core.py", line 782, in main
rv = self.invoke(ctx)
File "/Users/walsbr/aced/data_model/venv/lib/python3.9/site-packages/click/core.py", line 1259, in invoke
return _process_result(sub_ctx.command.invoke(sub_ctx))
File "/Users/walsbr/aced/data_model/venv/lib/python3.9/site-packages/click/core.py", line 1066, in invoke
return ctx.invoke(self.callback, **ctx.params)
File "/Users/walsbr/aced/data_model/venv/lib/python3.9/site-packages/click/core.py", line 610, in invoke
return callback(*args, **kwargs)
File "/Users/walsbr/aced/data_model/venv/lib/python3.9/site-packages/click/decorators.py", line 21, in new_func
return f(get_current_context(), *args, **kwargs)
File "/Users/walsbr/aced/data_model/venv/lib/python3.9/site-packages/pfb_fhir/cli.py", line 211, in config
print(ctx.obj['model'].yaml())
AttributeError: 'Model' object has no attribute 'yaml'