[opam-devel] OPAM + Docker

[ygrek]

On Mon, 18 Nov 2013 10:43:59 -0800
Anil Madhavapeddy <anil at recoil.org> wrote:

> I've made some notes about using OPAM and Docker for easier local bulk builds here:
> http://anil.recoil.org/2013/11/15/docker-and-opam.html
> 
> One semi-interesting issue I've already discovered with depexts is that just a "ubuntu" tag isn't enough, since  some depexts are only valid in a specific version of Ubuntu.
> 
> This unfortunately feels like it might be a job for the constraint system and not for flat tags (since I want to say >precise or <saucy).  We could do it with flat tags for now, but I have a bad feeling that it'll get unmanageable quite quickly..

I personally dislike this depexts field to mention OS packages at all.
Maybe it's better to specify which external libraries are needed (as .so or as pkg-config files) and then
use native OS way (at installation time) to determine which package contains that .so or .pc file (e.g. apt-file on Debian).
If apt-file is not present it is at least possible to tell (with dpkg -S or ldconfig -p) whether the .so is present and what is
precisely needed for the build to succeed (and mention how to find the needed package manually).
It may be even possible to gater information about .so files automatically - by inspecting generated cmxa and cma
files with ocamlobjinfo - so it can be done by ocamlot or something like that.

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