Discussed with @diml offline.

Switching to library from (wrapped false) to (wrapped true) usually mean that you break most package depending on you. Dune should support a transition mode that will emit warning if modules are accessed directly.

In that mode, for every module in the lib:

• dune would generate {MOD}.ml-gen
• compile {MOD}.ml-gen to {MOD}.cm{i,o,x}
• include these new implementations in the archive.

{MOD}.ml-gen files would look like:

include Lib__{MOD} [@@deprecated "Use Lib.{MOD} instead."]