build: Use gitignore.nix to fetch the src

flake.lock

@@ -18,6 +18,26 @@
         "type": "github"
       }
     },
+    "gitignore": {
+      "inputs": {
+        "nixpkgs": [
+          "nixpkgs"
+        ]
+      },
+      "locked": {
+        "lastModified": 1660459072,
+        "narHash": "sha256-8DFJjXG8zqoONA1vXtgeKXy68KdJL5UaXR8NtVMUbx8=",
+        "owner": "hercules-ci",
+        "repo": "gitignore.nix",
+        "rev": "a20de23b925fd8264fd7fad6454652e142fd7f73",
+        "type": "github"
+      },
+      "original": {
+        "owner": "hercules-ci",
+        "repo": "gitignore.nix",
+        "type": "github"
+      }
+    },
     "nixpkgs": {
       "locked": {
         "lastModified": 1688859638,
@@ -55,6 +75,7 @@
     "root": {
       "inputs": {
         "flake-parts": "flake-parts",
+        "gitignore": "gitignore",
         "nixpkgs": "nixpkgs"
       }
     }

flake.nix

@@ -3,9 +3,14 @@
   inputs = {
     nixpkgs.url = "github:NixOS/nixpkgs/nixpkgs-unstable";
     flake-parts.url = "github:hercules-ci/flake-parts";
+
+    gitignore = {
+      url = "github:hercules-ci/gitignore.nix";
+      inputs.nixpkgs.follows = "nixpkgs";
+    };
   };
 
-  outputs = inputs@{ flake-parts, ... }:
+  outputs = inputs@{ flake-parts, gitignore, ... }:
     flake-parts.lib.mkFlake { inherit inputs; } {
       systems = [ "aarch64-darwin" "x86_64-linux" "aarch64-linux" ];
 
@@ -19,6 +24,7 @@
           elixir = beamPackages.elixir_1_15;
 
           inherit (pkgs.stdenv) isDarwin;
+          inherit (gitignore.lib) gitignoreSource;
         in
         {
           devShells.default = pkgs.mkShell {
@@ -40,7 +46,7 @@
           packages.default = beamPackages.mixRelease {
             inherit pname version;
 
-            src = ./.;
+            src = gitignoreSource ./.;
             mixNixDeps = import ./mix.nix { inherit lib beamPackages; };
           };