xemu: cosmetic rewrite

- Use rec-less, overlay-style overridable attributes for stdenv.mkDerivation;
- Reorder the lists and sets in asciibetical order;
- Format the code.

pkgs/applications/emulators/xemu/default.nix

@@ -1,67 +1,67 @@
-{ stdenv
+{ lib
+, stdenv
 , fetchFromGitHub
-, lib
-, makeDesktopItem
-, copyDesktopItems
-, pkg-config
-, python3
-, ninja
-, meson
-, which
-, perl
-, wrapGAppsHook
-, glib
-, gtk3
-, libpcap
-, openssl
-, libepoxy
-, libsamplerate
 , SDL2
 , SDL2_image
-, mesa
-, libdrm
-, libGLU
+, copyDesktopItems
 , gettext
+, glib
+, gtk3
+, libGLU
+, libdrm
+, libepoxy
+, libpcap
+, libsamplerate
+, makeDesktopItem
+, mesa
+, meson
+, ninja
+, openssl
+, perl
+, pkg-config
+, python3
 , vte
+, which
+, wrapGAppsHook
 }:
 
-stdenv.mkDerivation rec {
+stdenv.mkDerivation (self: {
   pname = "xemu";
   version = "0.7.84";
 
   src = fetchFromGitHub {
     owner = "xemu-project";
     repo = "xemu";
-    rev = "v${version}";
-    fetchSubmodules = true;
+    rev = "v${self.version}";
     hash = "sha256-pEXjwoQKbMmVNYCnh5nqP7k0acYOAp8SqxYZwPzVwDY=";
+    fetchSubmodules = true;
   };
 
   nativeBuildInputs = [
+    copyDesktopItems
+    meson
+    ninja
+    perl
     pkg-config
     python3
     python3.pkgs.pyyaml
-    ninja
     which
-    meson
-    perl
     wrapGAppsHook
-    copyDesktopItems
   ];
 
   buildInputs = [
-    glib
-    gtk3
-    openssl
-    mesa
-    libepoxy
-    libdrm
-    libpcap
-    libsamplerate
     SDL2
-    libGLU
     SDL2_image
     gettext
+    glib
+    gtk3
+    libGLU
+    libdrm
+    libepoxy
+    libpcap
+    libsamplerate
+    mesa
+    openssl
     vte
   ];
 
@@ -80,23 +80,26 @@ stdenv.mkDerivation rec {
 
   buildFlags = [ "qemu-system-i386" ];
 
-  desktopItems = [(makeDesktopItem {
-    name = "xemu";
-    desktopName = "xemu";
-    exec = "xemu";
-    icon = "xemu";
-  })] ;
+  desktopItems = [
+    (makeDesktopItem {
+      name = "xemu";
+      desktopName = "xemu";
+      exec = "xemu";
+      icon = "xemu";
+    })
+  ];
 
   preConfigure = let
+    # When the data below can't be obtained through git, the build process tries
+    # to run `XEMU_COMMIT=$(cat XEMU_COMMIT)` (and similar)
     branch = "master";
     commit = "d8fa50e524c22f85ecb2e43108fd6a5501744351";
+    inherit (self) version;
   in ''
     patchShebangs .
     configureFlagsArray+=("--extra-cflags=-DXBOX=1 -Wno-error=redundant-decls")
     substituteInPlace ./scripts/xemu-version.sh \
       --replace 'date -u' "date -d @$SOURCE_DATE_EPOCH '+%Y-%m-%d %H:%M:%S'"
-    # If the versions can't be obtained through git, the build process tries
-    # to run `XEMU_COMMIT=$(cat XEMU_COMMIT)` (and similar)
     echo '${commit}' > XEMU_COMMIT
     echo '${branch}' > XEMU_BRANCH
     echo '${version}' > XEMU_VERSION
@@ -128,4 +131,4 @@ stdenv.mkDerivation rec {
     maintainers = with maintainers; [ ];
     license = licenses.gpl2Plus;
   };
-}
+})