[bug#45498] [PATCH 00/12] Add ocaml-merlin.

[pukkamustard]

Thank you for the feedback! v2 of patch series coming shortly...

I was not aware of the `ocaml4.07-variant` property. It makes 
things a
lot nicer!

I've added it for `ocaml-markup` and `ocaml-odoc` and also
`ocaml-sexplib0`, `ocaml-parsexp`, `ocaml-base` and 
`ocaml-sexplib`.

This makes `ocaml4.07-*` vanish from lot of places in favor of
`(package-with-ocaml4.07 *)`.

> Have you tried updating dune to the latest version that builds 
> with
> ocaml 4.07?

Not yet. For ocaml-markup 1.0.0 the problem is that the dune file
version is set to 2.7. Any dune below 2.7.x will probably not 
work.

For other packages it might work...

> >   This is quite cumbersome as two trees of OCaml packages need 
> >   to be
> >   maintained.
>
> Actually 3, there are ocaml 4.07, 4.09 and 4.11 currently. I'm 
> working
> on a bootstrap for ocaml 4.07 (ocaml builds from a binary 
> version of
> itself), so I don't think it'll disappear soon, but at least we 
> can try
> and make ocaml4.07-* packages disappear :)

\o/ Looking forward to the bootstrap!

With the `ocaml4.*-variant` property managing the 3 trees does not 
seem
so bad after all.

Currently there are a lot of packages only for 4.07. It would be 
nicer
to have packages for default compiler and when needed variants for 
older
compilers.

I plan to do some OCaml hacking in the next months and will send 
in
patches toward this, if that is ok.

> > - Some OCaml libraries have dependencies in `inputs` that seem 
> > to be
> > required from packages using the libraries.  E.g. 
> > `ocaml-yojson`
> > depends on `ocaml-biniou`. Packages depending on `ocaml-yojson` 
> > need
> > to manually add `ocaml-biniou` to their inputs. Would it 
> > work/make
> > sense to add `ocaml-biniou` to `propagated-inputs` of 
> > `ocaml-yojson`?
>
> Yeah, could you provide an additional patch for that?

Done. Patch 13 in v2.

-pukkamustard