Failure when trying to save session

[astrofrog]

I tried to save a session set up with the W5 example:

Traceback (most recent call last):


File "/Users/tom/miniconda3/envs/gluedev/lib/python3.4/site-packages/glueviz-0.5.0-py3.4.egg/glue/core/application_base.py", line 25, in wrapper

    return func(*args, **kwargs)


File "/Users/tom/miniconda3/envs/gluedev/lib/python3.4/site-packages/glueviz-0.5.0-py3.4.egg/glue/core/application_base.py", line 94, in save_session

    state = gs.dumps(indent=2)


File "/Users/tom/miniconda3/envs/gluedev/lib/python3.4/site-packages/glueviz-0.5.0-py3.4.egg/glue/core/state.py", line 339, in dumps

    return json.dumps(result, indent=indent, default=self.json_default)


File "/Users/tom/miniconda3/envs/gluedev/lib/python3.4/json/__init__.py", line 237, in dumps
    **kw).encode(obj)


File "/Users/tom/miniconda3/envs/gluedev/lib/python3.4/json/encoder.py", line 194, in encode

    chunks = list(chunks)


File "/Users/tom/miniconda3/envs/gluedev/lib/python3.4/json/encoder.py", line 422, in _iterencode

    yield from _iterencode_dict(o, _current_indent_level)


File "/Users/tom/miniconda3/envs/gluedev/lib/python3.4/json/encoder.py", line 396, in _iterencode_dict

    yield from chunks


File "/Users/tom/miniconda3/envs/gluedev/lib/python3.4/json/encoder.py", line 396, in _iterencode_dict
    yield from chunks


File "/Users/tom/miniconda3/envs/gluedev/lib/python3.4/json/encoder.py", line 430, in _iterencode

    yield from _iterencode(o, _current_indent_level)


File "/Users/tom/miniconda3/envs/gluedev/lib/python3.4/json/encoder.py", line 427, in _iterencode

    raise ValueError("Circular reference detected")

ValueError: Circular reference detected


[astrofrog]

This happens only when trying to include the data files.

[astrofrog]

This is actually due to the units which are Astropy units in this case. PR forthcoming.

[astrofrog]

For now, we simply don't allow anything but string units on Components (astropy units convert gracefully to strings)