[PATCH 0/7] Enable Elixir packages that depend on Erlang packages to build

Hello lylip,

It's great to see progress!

I suggest the next objective is to enable Elixir packages that depend on Erlang

packages to build. For instance, the Elixir package [telemetry_metrics] depends on the

Erlang telemetry package and is a dependency of the Elixir Phoenix package.

While reviewing the code of the Rebar build system, we noticed the use of the

[skip_deps] Rebar flag, which is ignored by Rebar:

?????

? $ guix shell rebar3 -- rebar3 help compile

? […]

? -d, --deps_only Only compile dependencies, no project apps will be

? built.

?????

So, to build Elixir packages that depend on Erlang, the necessary steps inlcude:

1) Updating the Rebar build system to align with the current usages of Rebar.

2) Allowing Elixir to access Erlang compiled libraries as discussed in [issue 66801].

If the following plan is agreed upon, then we will have an Elixir package that

depends on an Erlang package to build, specifically `telemetry_metrics'. Patches in the

series will have these objectives:

1. ? Update the Rebar build system to align with the current usages of Rebar.

2. ? Update the Erlang build system to install libraries under `lib/erlang/X.Y' as discussed in issue 66801.

3. ? Update the Erlang package so that `GUIX_ERL_LIBS' gather all libraries installed under `lib/erlang/X.Y'.

4. ? Update the Erlang package to wrap its binaires so that they have access to

compiled libraries represented by `GUIX_ERL_LIBS'.

5. ? Add the Erlang Telemetry package.

6. ? Update the Elixir package so that it has access to Erlang packages represented by `GUIX_ERL_LIBS'.

7. ? Add the Elixir package `telemetry_metrics'.

If the corresponding patch series is merged, additional packages (whether Erlang,

Elixir, or other types) will be incorporated until Phoenix package builds.

What do you think of this plan?

–

Regards,

phf

[telemetry_metrics] https://hex.pm/packages/telemetry_metrics

[skip_deps] https://git.savannah.gnu.org/cgit/guix.git/tree/guix/build-system/rebar.scm?id=f410d49eb24db4eecae054dfe136464bc92ba8a3#n103

[issue 66801] https://issues.guix.gnu.org/66801#75

Am Montag, dem 18.12.2023 um 14:02 +0100 schrieb Pierre-Henry Fröhring:

Since we typically disable phoning home (including telemetry), I don't

think having a telemetry package in Guix would be good optics :)

Perhaps you can think of another example package but still follow the

steps laid out above?

Cheers

Dear lylip,

The [yaml_elixir] package should fit the bill as it calls [yamerl]. I have

got everything working here. I am in the process of crafting the various

patches. I have written a literate programming implementation of the rebar

build system to document the reasoning for future references. The code in

the post actually runs. Could you please review the reasoning? I will add

your remarks to the post. Here is the post:

Thank you.

--

Regards,

-- phf

[yaml_elixir] https://hex.pm/packages/yaml_elixir

[yamerl] https://hex.pm/packages/yamerl