File "aliases.ml", line 17, characters 12-13:
17 | module A' = A (* missing a.cmi *)
                 ^
Warning 49 [no-cmi-file]: no cmi file was found in path for module A

File "aliases.ml", line 18, characters 12-13:
18 | module B' = B (* broken b.cmi *)
                 ^
Warning 49 [no-cmi-file]: no valid cmi file was found in path for module B.
  b.cmi
is not a compiled interface