Since 4.01, ocamlbuild supports a new (experimental) option "-plugin-tag"
that allows to specify (built-in) ocamlbuild tags to use when compiling
myocamlbuild.ml. If you package coq-paths using findlib, you can then use

  ocamlbuild -use-ocamlfind -plugin-tag "package(coq-path)" ...


On Tue, Dec 10, 2013 at 11:20 PM, Gregory Malecha
<gmalecha@cs.harvard.edu>wrote:

> Hello --
>
> I have several ocamlbuild plugins that are very similar and I'm trying to
> figure out how to refactor them. I pulled out a bunch of definitions into
> another file (coq_paths.ml) and then said 'open Coq_paths' in '
> myocamlbuild.ml'. But when I do this, ocamlbuild can no longer build the
> plugin, not even if foo.cmo already exists in the _build directory.
>
> After hacking on this for a long time (and digging through the ocamlbuild
> sources) I found that you can write a Makefile that will build
> myocamlbuild.cmo using ocamlbuild without a plugin, and then manually link
> this against ocamlbuild.cmo and to produce a custom version of ocamlbuild
> that uses the plugin (this is exactly what ocamlbuild does). My question
> is: 'is there any nicer way to do this?' I'm including my Makefile below:
>
> OCAMLBUILDDIR=$(shell ocamlfind query ocamlbuild)
>
> all: _build/coq_builder
>         @ ./_build/coq_builder -no-plugin coq.otarget
>
> _build/coq_builder: myocamlbuild.ml coq_paths.ml
>         @ echo "building builder...."
>         @ ocamlbuild -cflags -I,`ocamlfind query ocamlbuild` -no-plugin
> myocamlbuild.cmo
>         @ ocamlc.opt unix.cma -I $(OCAMLBUILDDIR)
> $(OCAMLBUILDDIR)/ocamlbuildlib.cma \
>            _build/coq_paths.cmo _build/myocamlbuild.cmo \
>            $(OCAMLBUILDDIR)/ocamlbuild.cmo -o _build/coq_builder
>         @ echo "done"
>
> clean:
>         ocamlbuild -clean
>
> Thanks in advance.
>
> --
> gregory malecha
> http://www.people.fas.harvard.edu/~gmalecha/
>