This is a quick hack so that anyone else who runs this from source doesn't have to spend
the time I spent tracking down why directory.list failed silently.
There are two options that are much cleaner that come to mind:
- Subclass ImportException so as to differentiate missing requirements from
parse errors etc.
- Provide a method for plugins to list their requirements, so that
the loader can be the one to use imp.find_module().
Using imp.find_module() seems wise, either way.