The package set is not maintained. It is also not used by most of the
BEAM community. Removing it to allow a more useful set of tools fit to
the BEAM community in Nixpkgs.
<literal>packages</literal>: a set of package sets, each compiled with a specific Erlang/OTP version, e.g. <literal>beam.packages.erlangR19</literal>.
<literal>packages</literal>: a set of package builders (Mix and rebar3), each compiled with a specific Erlang/OTP version, e.g. <literal>beam.packages.erlangR19</literal>.
</para>
</listitem>
</itemizedlist>
@ -36,15 +36,11 @@
</para>
<para>
To create a package set built with a custom Erlang version, use the lambda, <literal>beam.packagesWith</literal>, which accepts an Erlang/OTP derivation and produces a package set similar to <literal>beam.packages.erlang</literal>.
To create a package builder built with a custom Erlang version, use the lambda, <literal>beam.packagesWith</literal>, which accepts an Erlang/OTP derivation and produces a package builder similar to <literal>beam.packages.erlang</literal>.
</para>
<para>
Many Erlang/OTP distributions available in <literal>beam.interpreters</literal> have versions with ODBC and/or Java enabled. For example, there's <literal>beam.interpreters.erlangR19_odbc_javac</literal>, which corresponds to <literal>beam.interpreters.erlangR19</literal>.
</para>
<paraxml:id="erlang-call-package">
We also provide the lambda, <literal>beam.packages.erlang.callPackage</literal>, which simplifies writing BEAM package definitions by injecting all packages from <literal>beam.packages.erlang</literal> into the top-level context.
Many Erlang/OTP distributions available in <literal>beam.interpreters</literal> have versions with ODBC and/or Java enabled or without wx (no observer support). For example, there's <literal>beam.interpreters.erlangR22_odbc_javac</literal>, which corresponds to <literal>beam.interpreters.erlangR22</literal> and <literal>beam.interpreters.erlangR22_nox</literal>, which corresponds to <literal>beam.interpreters.erlangR22</literal>.
</para>
</section>
@ -55,7 +51,7 @@
<title>Rebar3</title>
<para>
We provide a version of Rebar3, which is the normal, unmodified Rebar3, under <literal>rebar3</literal>. We also provide a helper to fetch Rebar3 dependencies from a lockfile under <literal>fetchRebar3Deps</literal>.
We provide a version of Rebar3, under <literal>rebar3</literal>. We also provide a helper to fetch Rebar3 dependencies from a lockfile under <literal>fetchRebar3Deps</literal>.
</para>
</section>
@ -72,32 +68,14 @@
<title>How to Install BEAM Packages</title>
<para>
BEAM packages are not registered at the top level, simply because they are not relevant to the vast majority of Nix users. They are installable using the <literal>beam.packages.erlang</literal> attribute set (aliased as <literal>beamPackages</literal>), which points to packages built by the default Erlang/OTP version in Nixpkgs, as defined by <literal>beam.interpreters.erlang</literal>. To list the available packages in <literal>beamPackages</literal>, use the following command:
</para>
<screen>
<prompt>$ </prompt>nix-env -f "<nixpkgs>" -qaP -A beamPackages
beamPackages.esqlite esqlite-0.2.1
beamPackages.goldrush goldrush-0.1.7
beamPackages.ibrowse ibrowse-4.2.2
beamPackages.jiffy jiffy-0.14.5
beamPackages.lager lager-3.0.2
beamPackages.meck meck-0.8.3
beamPackages.rebar3-pc pc-1.1.0
</screen>
<para>
To install any of those packages into your profile, refer to them by their attribute path (first column):
BEAM builders are not registered at the top level, simply because they are not relevant to the vast majority of Nix users.
To install any of those builders into your profile, refer to them by their attribute path <literal>beamPackages.rebar3</literal>:
The attribute path of any BEAM package corresponds to the name of that particular package in <linkxlink:href="https://hex.pm">Hex</link> or its OTP Application/Release name.
The Nix function, <literal>buildRebar3</literal>, defined in <literal>beam.packages.erlang.buildRebar3</literal> and aliased at the top level, can be used to build a derivation that understands how to build a Rebar3 project. For example, we can build <link
xlink:href="https://github.com/erlang-nix/hex2nix">hex2nix</link> as follows:
Such derivations are callable with <literal>beam.packages.erlang.callPackage</literal> (see <xref
linkend="erlang-call-package"/>). To call this package using the normal <literal>callPackage</literal>, refer to dependency packages via <literal>beamPackages</literal>, e.g. <literal>beamPackages.ibrowse</literal>.
</para>
<para>
Notably, <literal>buildRebar3</literal> includes <literal>beamDeps</literal>, while <literal>stdenv.mkDerivation</literal> does not. BEAM dependencies added there will be correctly handled by the system.
The Nix function, <literal>buildRebar3</literal>, defined in <literal>beam.packages.erlang.buildRebar3</literal> and aliased at the top level, can be used to build a derivation that understands how to build a Rebar3 project.
</para>
<para>
@ -152,30 +102,6 @@ buildRebar3 rec {
Erlang.mk functions similarly to Rebar3, except we use <literal>buildErlangMk</literal> instead of <literal>buildRebar3</literal>.
Often, we simply want to access a valid environment that contains a specific package and its dependencies. We can accomplish that with the <literal>env</literal> attribute of a derivation. For example, let's say we want to access an Erlang REPL with <literal>ibrowse</literal> loaded up. We could do the following:
</para>
<screen>
<prompt>$ </prompt><userinput>nix-shell -A beamPackages.ibrowse.env --run "erl"</userinput>
Notice the <literal>-A beamPackages.ibrowse.env</literal>. That is the key to this functionality.
</para>
</section>
<sectionxml:id="creating-a-shell">
<title>Creating a Shell</title>
<para>
Getting access to an environment often isn't enough to do real development. Usually, we need to create a <literal>shell.nix</literal> file and do our development inside of the environment specified therein. This file looks a lot like the packaging described above, except that <literal>src</literal> points to the project root and we call the package directly.
</para>
<para>
Usually, we need to create a <literal>shell.nix</literal> file and do our development inside of the environment specified therein. Just install your version of erlang and other interpreter, and then user your normal build tools.
As an example with elixir:
</para>
<programlisting>
{ pkgs ? import "<nixpkgs"> {} }:
@ -311,114 +136,24 @@ with pkgs;
let
f = { buildRebar3, ibrowse, jsx, erlware_commons }:
Using a <literal>shell.nix</literal> as described (see <xref
linkend="creating-a-shell"/>) should just work. Aside from <literal>test</literal>, <literal>plt</literal>, and <literal>analyze</literal>, the Make targets work just fine for all of the build derivations.
<title>Generating Packages from Hex with <literal>hex2nix</literal></title>
<para>
Updating the <linkxlink:href="https://hex.pm">Hex</link> package set requires <link
xlink:href="https://github.com/erlang-nix/hex2nix">hex2nix</link>. Given the path to the Erlang modules (usually <literal>pkgs/development/erlang-modules</literal>), it will dump a file called <literal>hex-packages.nix</literal>, containing all the packages that use a recognized build system in <link
xlink:href="https://hex.pm">Hex</link>. It can't be determined, however, whether every package is buildable.
</para>
<para>
To make life easier for our users, try to build every <link
xlink:href="https://hex.pm">Hex</link> package and remove those that fail. To do that, simply run the following command in the root of your <literal>nixpkgs</literal> repository:
</para>
<screen>
<prompt>$ </prompt>nix-build -A beamPackages
</screen>
<para>
That will attempt to build every package in <literal>beamPackages</literal>. Then manually remove those that fail. Hopefully, someone will improve <link
xlink:href="https://github.com/erlang-nix/hex2nix">hex2nix</link> in the future to automate the process.