This isn't broken! Our import completion correctly traverses directories which do not contain an __init__.py, since #792, because empty __init__.py files are no longer required for namespace packages.

• Maybe we shouldn't crawl these at all. Apparently unittest doesn't crawl them, a sort of similar problem. At some point in the past, IPython skipped these too.

• Maybe we should use different crawling logic for the current directory that bpython is run from than we do for other locations on sys.path: namespace packages in other locations will still be picked up, but running bpython from a filesystem path which contains a massive node_modules directory or similar won't chew up CPU. Users who manually add e.g. their home directory to sys.path would still see this issue.

We could implement a (user-configurable) skip list which is checked before traversing into directories. We could make it default to node_modules, .git, and maybe other well known directories which won't contain Python modules.