For the record, we checked upstream (with Luc Maranget, who wrote the latex->info converter used by the OCaml manual) and production of info files still reliable works upstream. I didn't follow all the details but apparently the build process produced a temporary file (ocaml.info.body) that might have confused Debian packagers, and Luc removed it from trunk: https://github.com/ocaml/ocaml/commit/533e0cdd29cc70773703f47acede8ee45aea5591