I have a buffer with contents:
With point behind /, I get proper completion. Note that nothing has been sourced yet.
But if I uncomment the first form, I get Namespace not found error when I try to complete.
After sourcing, the problem disappears.
It's a bit of a nuisance, since at the point when I need completion,
the code isn't in the valid state. And I'm currently just editing
within org-babel source blocks, so I need to drop out of source block etc.