xo-arena: + nix build

pkgs/xo-arena.nix

@@ -0,0 +1,28 @@
+{
+  # nixpkgs dependencies
+  stdenv, cmake, catch2,
+
+  # xo dependencies
+  xo-cmake,
+#  xo-refcnt,
+  xo-reflectutil,
+  xo-indentlog,
+} :
+
+stdenv.mkDerivation (finalattrs:
+  {
+    name = "xo-arena";
+
+    src = ../xo-arena;
+
+    cmakeFlags = ["-DCMAKE_MODULE_PATH=${xo-cmake}/share/cmake"];
+    doCheck = true;
+    nativeBuildInputs = [
+      cmake catch2 xo-cmake
+    ];
+    propagatedBuildInputs = [
+#      xo-refcnt
+      xo-reflectutil
+      xo-indentlog
+    ];
+  })