I am going to give the workaround a try tomorrow.

Regarding the bug, are you sure about that?
When I load the common libs in utop, the module is loaded.

utop # #require "compiler-libs.common";;
─( 21:39:56 )─< command 1
>────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────{
counter: 0 }─utop # #typeof "Compplugin";;
module Compplugin : sig val load : string -> unit end


So if the module is not part of the common library, how do I reproduce
the actual bug?

Am 07.11.2016 um 21:30 schrieb Gabriel Scherer:
> Compplugin is a module from the compiler distribution that indeed is new
> in 4.04.0. It is not included in ocamlcommon.cma. It is part of
> ocamlbytecomp.cma, but not of ocamloptcomp.cma, and I believe that the
> latter omission is a bug (as Optcompile depends on it), so maybe it
> should really be in ocamlcommon.cma.
> 
> This looks like an upstream bug (in the OCaml distribution). Could you
> open a Mantis issue?
> 
> As a workaround, you may be able to link to the compplugin module
> separately, it is installed in the $(ocamlfind query compiler-libs)
> directory.
> 
> On Mon, Nov 7, 2016 at 3:10 PM, Christoph Höger
> <christoph.hoeger@tu-berlin.de <mailto:christoph.hoeger@tu-berlin.de>>
> wrote:
> 
>     Dear all,
> 
>     today I attempted to migrate my stack towards 4.04.0 - unfortunately
>     ppx_monadic is not yet available for that language version. I attempted
>     to build it myself, but to no avail:
> 
>     Error: Required module `Compplugin' is unavailable
> 
>     This error is newly introduced into 4.04.0 (and does not exist in the
>     HEAD version). Compplugin should be provided by compilerlibs.common, so
>     I assume I need to fix the build system somehow.
> 
>     Does anyone have any idea how to fix this?
> 
>     regards,
> 
>     Christoph
>     --
>     Christoph Höger
> 
>     Technische Universität Berlin
>     Fakultät IV - Elektrotechnik und Informatik
>     Übersetzerbau und Programmiersprachen
> 
>     Sekr. TEL12-2, Ernst-Reuter-Platz 7, 10587 Berlin
> 
>     Tel.: +49 (30) 314-24890 <tel:%2B49%20%2830%29%20314-24890>
>     E-Mail: christoph.hoeger@tu-berlin.de
>     <mailto:christoph.hoeger@tu-berlin.de>
> 
> 


-- 
Christoph Höger

Technische Universität Berlin
Fakultät IV - Elektrotechnik und Informatik
Übersetzerbau und Programmiersprachen

Sekr. TEL12-2, Ernst-Reuter-Platz 7, 10587 Berlin

Tel.: +49 (30) 314-24890
E-Mail: christoph.hoeger@tu-berlin.de