Seeking support for implementing Erlang/Rebar3 build system

[Hartmut Goebel <h.goebel@crazy-compilers.com>]

Hi,

I started working on a rebar3-build-system for Erlang packages. This a
somewhat crazy idea for me, since I have *not* clue about Erlang and how
it's building and packaging works. (I "just" want to have ejabberd in
guix :-) Based on this, I've already made good progress:

- packaged rebar3 and prepared packages for its dependencies (able to
bootstrap rebar3)
- preliminary rebar3-build-system is done, based on what I've seen at
Debian. (I've not found a  build-system for erlang in Nix.)
- basic importer for packages from hex.pm is done

You can find my WIP at
<https://gitlab.digitalcourage.de/htgoebel/guix/-/tree/HG-rebar-build-system>

To get this finished I'm seeking for someone having some experience
about Erlang. My questions are

- How does Erlang find the packages? Do we need to add a
native-search-paths (ERL_LIB?) to the erlang package?

- How to make rebar3 use already build packages and not try for fetch
them from a remote repo? Do we need to copy/link them somewhere, or set
some environment variable?

- Are there standard build targets for rebar3? Currently the
build-system has "compile", "xref" and "doc" - each in a phase of it's
own. Doe this actually make sense?

- Anything else?

-- 
Regards
Hartmut Goebel

| Hartmut Goebel          | h.goebel@crazy-compilers.com               |
| www.crazy-compilers.com | compilers which you thought are impossible |