There is a Nix functional called buildRebar3. We use this function to make a derivation that understands how to build the rebar3 project. For example, the epression we use to build the hex2nix project follows.

        {stdenv, fetchFromGitHub, buildRebar3, ibrowse, jsx, erlware_commons }:

          buildRebar3 rec {
            name = "hex2nix";
            version = "0.0.1";

            src = fetchFromGitHub {
              owner = "ericbmerritt";
              repo = "hex2nix";
              rev = "${version}";
              sha256 = "1w7xjidz1l5yjmhlplfx7kphmnpvqm67w99hd2m7kdixwdxq0zqg";
            };

          beamDeps = [ ibrowse jsx erlware_commons ];
        }
      

The only visible difference between this derivation and something like stdenv.mkDerivation is that we have added erlangDeps to the derivation. If you add your Beam dependencies here they will be correctly handled by the system.

If your package needs to compile native code via Rebar's port compilation mechenism. You should add compilePort = true; to the derivation.

Erlang.mk functions almost identically to Rebar. The only real difference is that buildErlangMk is called instead of buildRebar3

        { buildErlangMk, fetchHex,  cowlib, ranch }:
          buildErlangMk {
            name = "cowboy";
            version = "1.0.4";
            src = fetchHex {
              pkg = "cowboy";
              version = "1.0.4";
              sha256 =
                "6a0edee96885fae3a8dd0ac1f333538a42e807db638a9453064ccfdaa6b9fdac";
            };
            beamDeps  = [ cowlib ranch ];

            meta = {
              description = ''Small, fast, modular HTTP server written in
                            Erlang.'';
              license = stdenv.lib.licenses.isc;
              homepage = "https://github.com/ninenines/cowboy";
            };
        }
      

Mix functions almost identically to Rebar. The only real difference is that buildMix is called instead of buildRebar3

        { buildMix, fetchHex, plug, absinthe }:
        buildMix {
          name = "absinthe_plug";
          version = "1.0.0";
          src = fetchHex {
            pkg = "absinthe_plug";
            version = "1.0.0";
            sha256 =
              "08459823fe1fd4f0325a8bf0c937a4520583a5a26d73b193040ab30a1dfc0b33";
          };
          beamDeps  = [ plug absinthe];

          meta = {
            description = ''A plug for Absinthe, an experimental GraphQL
                            toolkit'';
            license = stdenv.lib.licenses.bsd3;
            homepage = "https://github.com/CargoSense/absinthe_plug";
         };
       }
      

We can leveral the support of the Derivation, regardless of which build Derivation is called by calling the commands themselv.s

# =============================================================================
# Variables
# =============================================================================

NIX_TEMPLATES := "$(CURDIR)/nix-templates"

TARGET := "$(PREFIX)"

PROJECT_NAME := thorndyke

NIXPKGS=../nixpkgs
NIX_PATH=nixpkgs=$(NIXPKGS)
NIX_SHELL=nix-shell -I "$(NIX_PATH)" --pure
# =============================================================================
# Rules
# =============================================================================
.PHONY= all test clean repl shell build test analyze configure install \
        test-nix-install publish plt analyze

all: build

guard-%:
        @ if [ "${${*}}" == "" ]; then \
                echo "Environment variable $* not set"; \
                exit 1; \
        fi

clean:
        rm -rf _build
        rm -rf .cache

repl:
        $(NIX_SHELL) --run "iex -pa './_build/prod/lib/*/ebin'"

shell:
        $(NIX_SHELL)

configure:
        $(NIX_SHELL) --command 'eval "$$configurePhase"'

build: configure
        $(NIX_SHELL) --command 'eval "$$buildPhase"'

install:
        $(NIX_SHELL) --command 'eval "$$installPhase"'

test:
        $(NIX_SHELL) --command 'mix test --no-start --no-deps-check'

plt:
        $(NIX_SHELL) --run "mix dialyzer.plt --no-deps-check"

analyze: build plt
        $(NIX_SHELL) --run "mix dialyzer --no-compile"

    

If you add the shell.nix as described and user rebar as follows things should simply work. Aside from the test, plt, and analyze the talks work just fine for all of the build Derivations.