Currently, with the introduction of support for dot-notation type hinting in 4.3.0, we also introduced a limitation to any recursive collection schemas. This limitation was partially addressed in 4.3.1, which allows self-referential types to compile, but does not fix the issue of indirectly self-referential types (e.g. where A references B and B references A).

There are other approaches we can take (see example here and here) to address the issue by limiting the depth of the recursion, and we may have to do this if it ends up affecting a significant number of users.