New issue 825: Creating an all_data object does not generate the field_info object. https://bitbucket.org/yt_analysis/yt/issue/825/creating-an-all_data-object-d... Nathan Goldbaum: The following script and traceback illustrates the issue: ``` #!python import yt ds = yt.load('IsolatedGalaxy/galaxy0030/galaxy0030') ad = ds.all_data() print ad.quantities.total_mass() ``` ``` File "test.py", line 7, in <module> print ad.quantities.total_mass() File "/Users/goldbaum/Documents/yt-hg/yt/data_objects/derived_quantities.py", line 188, in __call__ fi = self.data_source.pf.field_info AttributeError: 'EnzoDataset' object has no attribute 'field_info' ``` Adding a call to ds.index before the call to the `total_mass` derived quantity eliminates the error.