### Background
#1102 changed how `Interpreter.Use` interprets export paths such that the last path component is stripped and used as the package name. This resulted in #1139 - attempting to Use an export with only one path component, such as `foo`, would result in the import path being `.`.
### Breaking API Change
This PR changes the signature of `Interpreter.Use` from `Use(Exports)` to `Use(Exports) error`.
### Fix for #1139
With this PR, if Use is called with an incomplete export path, such as `foo`, Use will return an error.