alacritty-ligatures: refactor into standalone file

pkgs/applications/terminal-emulators/alacritty-ligatures/default.nix

@@ -0,0 +1,53 @@
+{ stdenv
+, lib
+, fetchFromGitHub
+
+, alacritty
+
+, fontconfig
+, freetype
+, libglvnd
+, libxcb
+}:
+
+alacritty.overrideAttrs (oldAttrs: rec {
+  pname = "${oldAttrs.pname}-ligatures";
+  version = "0.7.1.20210107.gada2680";
+
+  src = fetchFromGitHub {
+    owner = "zenixls2";
+    repo = "alacritty";
+    fetchSubmodules = true;
+    rev = "df24940a9ccf7ba897fa3167046ee8b181342d8f";
+    sha256 = "sha256-2Th2aojTN36MgYSFXiACcBkTpTou/X1Ub5JR2sgZa34=";
+  };
+
+  cargoDeps = oldAttrs.cargoDeps.overrideAttrs (lib.const {
+    name = "${pname}-${version}-vendor.tar.gz";
+    inherit src;
+    outputHash = "sha256-weGYh5qeaOHFfq2nf0UdsuIZud+7/8SCD0g0BAjoJIc=";
+  });
+
+  ligatureInputs = [
+    fontconfig
+    freetype
+    libglvnd
+    stdenv.cc.cc.lib
+    libxcb
+  ];
+
+  buildInputs = (oldAttrs.buildInputs or [ ]) ++ ligatureInputs;
+
+  # HACK: One of the ligature libraries required the C++ stdlib at runtime,
+  # and I can't work out a better way to push it to the RPATH.
+  postInstall = lib.optional (!stdenv.isDarwin) ''
+    patchelf \
+      --set-rpath ${lib.makeLibraryPath ligatureInputs}:"$(patchelf --print-rpath $out/bin/alacritty)" \
+      $out/bin/alacritty
+  '';
+
+  meta = oldAttrs.meta // {
+    description = "Alacritty with ligature patch applied";
+    homepage = "https://github.com/zenixls2/alacritty/tree/ligature";
+  };
+})

pkgs/top-level/all-packages.nix

@@ -2,47 +2,7 @@
 
 rec {
   # Alacritty with the unmerged ligature patches applied.
-  alacritty-ligatures = pkgs.alacritty.overrideAttrs (oldAttrs: rec {
+  alacritty-ligatures = pkgs.callPackage ../applications/terminal-emulators/alacritty-ligatures { };
-    pname = "${oldAttrs.pname}-ligatures";
-    version = "0.7.1.20210107.gada2680";
-
-    src = pkgs.fetchFromGitHub {
-      owner = "zenixls2";
-      repo = "alacritty";
-      fetchSubmodules = true;
-      rev = "df24940a9ccf7ba897fa3167046ee8b181342d8f";
-      sha256 = "sha256-2Th2aojTN36MgYSFXiACcBkTpTou/X1Ub5JR2sgZa34=";
-    };
-
-    cargoDeps = oldAttrs.cargoDeps.overrideAttrs (pkgs.lib.const {
-      name = "${pname}-${version}-vendor.tar.gz";
-      inherit src;
-      outputHash = "sha256-weGYh5qeaOHFfq2nf0UdsuIZud+7/8SCD0g0BAjoJIc=";
-    });
-
-    ligatureInputs = [
-      pkgs.fontconfig
-      pkgs.freetype
-      pkgs.libglvnd
-      pkgs.stdenv.cc.cc.lib
-      pkgs.xlibs.libxcb
-    ];
-
-    buildInputs = (oldAttrs.buildInputs or []) ++ ligatureInputs;
-
-    # HACK: One of the ligature libraries required the C++ stdlib at runtime,
-    # and I can't work out a better way to push it to the RPATH.
-    postInstall = pkgs.lib.optional (!pkgs.stdenv.isDarwin) ''
-      patchelf \
-        --set-rpath ${pkgs.lib.makeLibraryPath ligatureInputs}:"$(patchelf --print-rpath $out/bin/alacritty)" \
-        $out/bin/alacritty
-    '';
-
-    meta = oldAttrs.meta // {
-      description = "Alacritty with ligature patch applied";
-      homepage = "https://github.com/zenixls2/alacritty/tree/ligature";
-    };
-  });
 
   amdgpu-fan = pkgs.callPackage ../tools/misc/amdgpu-fan { };