See also this older bug: http://caml.inria.fr/mantis/view.php?id=5628

For all OCaml versions where #remove_directory is available, findlib
now temporarily adds compiler-libs to the path while initializing
itself for the toploop, and removes the compiler-libs directory
afterwards. So at least findlib isn't dependent on having topdirs.cmi
still in the main stdlib directory.

I don't know for other users of topdirs.

Gerd

Am Dienstag, den 16.08.2016, 16:04 +0300 schrieb Kakadu:
> Hey,
> 
> After introducing compiler-libs we have starting getting a warning
> when we use compiler-libs as ocamlfind package.
> 
> findlib: [WARNING] Interface topdirs.cmi occurs in several
> directories: /home/kakadu/.opam2/4.02.3/lib/ocaml,
> /home/kakadu/.opam2/4.02.3/lib/ocaml/compiler-libs
> 
> (* It has its own mantis issue [1] where gasche have said that we
> should discuss it in the mail list before fixing it. *)
> 
> It happens because we install topdirs.cmi both to `ocamlc -where` and
> `ocamlc -where`/compiler-libs. Of course these are identical files
> with the same size and MD5 checksum.
> 
> The obvious choice should be not installing this file to `ocamlc
> -where` (I) or to `ocamlc -where`/compiler-libs (II).
> 
> (I) Seems to be the right solution architecture-wise but it can
> introduce backward-incompatibility in OPAM: after initialization it
> puts some code into ~/.ocamlinit which relies on topdirs.cmi [2].
> Personally, I removed this line from my ~/.ocamlinit because it seems
> useless for my case. So, by removing `topdirs.cmi` from `ocamlc
> -where` we should probably release bugfix release for opam.
> 
> (II) removing `topdirs.cmi` from `ocamlfind query compiler-libs`
> means
> that we split files for this library between two directories which is
> not good in general. Also, there is a probability that we can break
> compilation of some packages but I think that it is unlikely.
> 
> Patches implementing both approaches are very likely to be very
> straightforward. We only need to decide right solution. Maybe we can
> even get it into 4.04.
> 
> Kakadu
> 
> [1] http://caml.inria.fr/mantis/view.php?id=6754
> [2]
> let () =
>   try Topdirs.dir_directory (Sys.getenv "OCAML_TOPLEVEL_PATH")
>   with Not_found -> ()
> ;;
> 
-- 
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Gerd Stolpmann, Darmstadt, Germany    gerd@gerd-stolpmann.de
My OCaml site:          http://www.camlcity.org
Contact details:        http://www.camlcity.org/contact.html
Company homepage:       http://www.gerd-stolpmann.de
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