1 files changed, 20 insertions, 0 deletions
diff --git a/third_party/lisp/closer-mop.nix b/third_party/lisp/closer-mop.nix
new file mode 100644
index 000000000000..a63f520f22cd
--- /dev/null
+++ b/third_party/lisp/closer-mop.nix
@@ -0,0 +1,20 @@
+# Closer to MOP is a compatibility layer that rectifies many of the
+# absent or incorrect CLOS MOP features across a broad range of Common
+# Lisp implementations
+{ pkgs, ... }:
+
+let src = pkgs.third_party.fetchFromGitHub {
+  owner = "pcostanza";
+  repo = "closer-mop";
+  rev = "e1d1430524086709a7ea8e0eede6849aa29d6276";
+  sha256 = "1zda6927379pmrsxpg29jnj6azjpa2pms9h7n1iwhy6q9d3w06rf";
+};
+in pkgs.nix.buildLisp.library {
+  name = "closer-mop";
+
+  srcs = [
+    "${src}/closer-mop-packages.lisp"
+    "${src}/closer-mop-shared.lisp"
+    "${src}/closer-sbcl.lisp"
+  ];
+}