I think that's just normal Nim behavior, right? If module A imports module B, and module B imports module C, then module A won't automatically see everything that B imported that was able to let B compile?
You could probably solve the probly by either: 1\. Import types.nim in bug.nim, to bring Foo into scope. 2\. Use an export statement in lib.nim, for Foo It's probably also possible for tne Nim compiler to automatically do some kind of export/import so that bug.nim can - while importing lib.nim, also "see" the required types from "types.nim"; at least to the extent so that bug.nim could typecheck correctly.
