Error when using option 'use_runs_db=False' #69
Description
There is an option for hax.init() to not use the runs database. However, this means that update_datasets does not do anything so that datasets will be None. Perhaps I am missing something here, but it seems that this means that you can specify not to use the runs database, but if you attempt to load anything, hax will give you an error since there is no variable listing datasets.
For now, I made a workaround by building this variable using the files in the main_data_paths, setting this as the run name. I can implement this and create a pull request, but maybe I am missing some secret configuration... Any thoughts?