Hi, Unfortunately it is not possible to compile camlp4 with OCaml >= 4.08.
But some well known packages depend on this preprocessor. E.g. :Haxe, lablgtk2 (therefore also: Unison and Coq). I don't see that these projects will be migrated to camlp5 or ppx in the near future. Therefore there are only 2 options from my point of view: 1. OCaml-4.07 and Ocaml >= 4.08 in [EXTRA]. 2. removal of Haxe, lablgtk2, Unison and Coq. I prefer 1. What do you think? Same issue discussed on Debian Bug Tracker: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=933722
