```
M-x customize-group RET ein-completion
```
Set `Ein:Completion Backend` to `ein:use-none-backend`, Set `State` to
`Save for Future Sessions`.
Also use `featurep` and `with-eval-after-load` to clean up the
subpackage requiring gymnastics.
The standard way to avoid this problem is to use autoload instead of require.
This way ESS is not required to compile and run EIN and it is only loaded if the user actually uses it.
