Breaking: require user to skip rustler compilation

Part of issue #9

Author: camelpunch

README.md

@@ -71,9 +71,7 @@ altogether: it compiles the dependency from scratch to let your project
 leverage Nix caching. This will mean that you'll have to wait for an initial
 compilation in your CI system.
 
-You must disable Rustler's compilation in your release environment as well.
-This is done at compile time in the Nix derivation, but your runtime
-configuration must match this.
+You must disable Rustler's compilation for all rustler_precompiled dependencies.
 
 e.g. for explorer, in `config/prod.exs`:
 

fixtures/example/config/config.exs

@@ -0,0 +1,6 @@
+import Config
+
+config :ex_keccak, ExKeccak, skip_compilation?: true
+config :explorer, Explorer.PolarsBackend.Native, skip_compilation?: true
+config :ex_secp256k1, ExSecp256k1.Impl, skip_compilation?: true
+config :tokenizers, Tokenizers.Native, skip_compilation?: true

fixtures/example/deps.nix

@@ -46,21 +46,11 @@ let
               ] ++ extendedPkgs.lib.lists.optional extendedPkgs.stdenv.isDarwin extendedPkgs.darwin.IOKit;
               doCheck = false;
             };
-        elixirConfig = pkgs.writeTextDir "config/config.exs" ''
-          import Config
-
-          config :ex_keccak, ExKeccak, skip_compilation?: true
-          config :explorer, Explorer.PolarsBackend.Native, skip_compilation?: true
-          config :ex_secp256k1, ExSecp256k1.Impl, skip_compilation?: true
-          config :tokenizers, Tokenizers.Native, skip_compilation?: true
-        '';
 
       in
       {
         nativeBuildInputs = [ extendedPkgs.cargo ];
 
-        appConfigPath = "${elixirConfig}/config";
-
         env.RUSTLER_PRECOMPILED_FORCE_BUILD_ALL = "true";
         env.RUSTLER_PRECOMPILED_GLOBAL_CACHE_PATH = "unused-but-required";
 

lib/deps_nix.ex

@@ -231,21 +231,11 @@ defmodule DepsNix do
                     ] ++ extendedPkgs.lib.lists.optional extendedPkgs.stdenv.isDarwin extendedPkgs.darwin.IOKit;
                     doCheck = false;
                   };
-              elixirConfig = pkgs.writeTextDir "config/config.exs" ''
-                import Config
-
-                config :ex_keccak, ExKeccak, skip_compilation?: true
-                config :explorer, Explorer.PolarsBackend.Native, skip_compilation?: true
-                config :ex_secp256k1, ExSecp256k1.Impl, skip_compilation?: true
-                config :tokenizers, Tokenizers.Native, skip_compilation?: true
-              '';
 
             in
             {
               nativeBuildInputs = [ extendedPkgs.cargo ];
 
-              appConfigPath = "${elixirConfig}/config";
-
               env.RUSTLER_PRECOMPILED_FORCE_BUILD_ALL = "true";
               env.RUSTLER_PRECOMPILED_GLOBAL_CACHE_PATH = "unused-but-required";