Generalize building of LFE

pkgs/development/beam-modules/default.nix

···
                        debugInfo = true;
                      };
 
-        lfe = callPackage ../interpreters/lfe { };
+        lfe = lfe_1_2;
+        lfe_1_2 = lib.callLFE ../interpreters/lfe/1.2.nix { inherit erlang buildRebar3; };
 
         # Non hex packages
         hex = callPackage ./hex {};

pkgs/development/beam-modules/lib.nix

···
         mkDerivation = pkgs.makeOverridable builder;
       };
 
+  /* Uses generic-builder to evaluate provided drv containing Elixir version
+  specific data.
+
+  drv: package containing version-specific args;
+  builder: generic builder for all Erlang versions;
+  args: arguments merged into version-specific args, used mostly to customize
+        dependencies;
+
+  Arguments passed to the generic-builder are overridable.
+
+  Please note that "mkDerivation" defined here is the one called from 1.2.nix
+  and similar files.
+  */
+  callLFE = drv: args:
+    let
+      inherit (stdenv.lib) versionAtLeast;
+      builder = callPackage ../interpreters/lfe/generic-builder.nix args;
+    in
+      callPackage drv {
+        mkDerivation = pkgs.makeOverridable builder;
+      };
+
 }

pkgs/development/interpreters/lfe/1.2.nix

···
+{ mkDerivation }:
+
+mkDerivation {
+  version = "1.2.1";
+  sha256 = "0j5gjlsk92y14kxgvd80q9vwyhmjkphpzadcswyjxikgahwg1avz";
+}

pkgs/development/interpreters/lfe/default.nix pkgs/development/interpreters/lfe/generic-builder.nix

···
-{ stdenv, fetchFromGitHub, erlang, makeWrapper, coreutils, bash, beamPackages }:
+{ stdenv, fetchFromGitHub, erlang, makeWrapper, coreutils, bash, buildRebar3 }:
 
-let
-  inherit (beamPackages) buildRebar3 buildHex;
-  proper = buildHex rec {
-    name    = "proper";
-    version = "1.1.1-beta";
-    sha256  = "0hnkhs761yjynw9382w8wm4j3x0r7lllzavaq2kh9n7qy3zc1rdx";
+{ baseName ? "lfe"
+, version
+, sha256 ? null
+, rev ? version
+, src ? fetchFromGitHub { inherit rev sha256; owner = "rvirding"; repo = "lfe"; }
+}:
 
-    configurePhase = ''
-      ${erlang}/bin/escript write_compile_flags include/compile_flags.hrl
-    '';
-  };
-in
-buildRebar3 rec {
-  name    = "lfe";
-  version = "1.2.1";
+buildRebar3 {
+  name = "${baseName}";
 
-  src = fetchFromGitHub {
-    owner  = "rvirding";
-    repo   = name;
-    rev    = version;
-    sha256 = "0j5gjlsk92y14kxgvd80q9vwyhmjkphpzadcswyjxikgahwg1avz";
-  };
+  inherit src version;
 
-  buildInputs = [ makeWrapper ];
-  beamDeps    = [ proper ];
+  buildInputs = [ erlang makeWrapper ];
   patches     = [ ./no-test-deps.patch ];
-  doCheck     = true;
-  checkTarget = "travis";
 
   # These installPhase tricks are based on Elixir's Makefile.
   # TODO: Make, upload, and apply a patch.
···
     install -m644 _build/default/lib/lfe/ebin/* $ebindir
 
     install -m755 -d $bindir
+
     for bin in bin/lfe{,c,doc,script}; do install -m755 $bin $bindir; done
 
     install -m755 -d $out/bin
···
     downloadPage = "https://github.com/rvirding/lfe/releases";
 
     license      = licenses.asl20;
-    maintainers  = with maintainers; [ yurrriq ];
+    maintainers  = with maintainers; [ yurrriq ankhers ];
     platforms    = platforms.unix;
   };
 }

pkgs/top-level/beam-packages.nix

···
     # `beam.packages.erlangR19.elixir`.
     inherit (packages.erlang) elixir elixir_1_5_rc elixir_1_4 elixir_1_3;
 
-    lfe = packages.erlang.lfe;
+    inherit (packages.erlang) lfe lfe_1_2;
   };
 
   # Helper function to generate package set with a specific Erlang version.