Extract Zig package builder

Consider moving to NUR or upstream?

nix/build-zig-package.nix

@@ -0,0 +1,57 @@
+{ stdenv
+, zig
+}:
+
+{ buildInputs ? [ ]
+, nativeBuildInputs ? [ ]
+, optimize ? "ReleaseSafe"
+, meta ? { }
+, ...
+}@args:
+
+stdenv.mkDerivation (args // {
+  nativeBuildInputs = nativeBuildInputs ++ [
+    zig
+  ];
+
+  buildInputs = buildInputs;
+
+  strictDeps = true;
+
+  configurePhase = args.configurePhase or ''
+    runHook preConfigure
+    runHook postConfigure
+  '';
+
+  ZIGFLAGS = args.ZIGFLAGS or [
+    "-Doptimize=${optimize}"
+  ];
+
+  # https://github.com/ziglang/zig/issues/6810 requires setting XDG_CACHE_HOME
+  # in all zig build phases. --cache-dir and --global-cache-dir do not prevent
+  # the builder from attempting to create the XDG cache.
+
+  buildPhase = args.buildPhase or ''
+    runHook preBuild
+    XDG_CACHE_HOME=_cache zig build $ZIGFLAGS
+    runHook postBuild
+  '';
+
+  doCheck = args.doCheck or true;
+  checkPhase = args.checkPhase or ''
+    runHook preCheck
+    XDG_CACHE_HOME=_cache zig build test $ZIGFLAGS
+    runHook postCheck
+  '';
+
+  installPhase = args.installPhase or ''
+    runHook preInstall
+    XDG_CACHE_HOME=_cache zig build install --prefix $out $ZIGFLAGS
+    runHook postInstall
+  '';
+
+  meta = {
+    # default to Zig's platforms
+    platforms = zig.meta.platforms;
+  } // meta;
+})