wip - buildable state

overlays/libvirt-python313-fix/default.nix

@@ -0,0 +1,28 @@
+{ ... }:
+
+final: prev:
+let
+  python313ForCeph =
+    let
+      base = final.python313;
+    in
+    base
+    // {
+      override = args:
+        base.override (args // {
+          packageOverrides = self: super:
+            (if args ? packageOverrides then args.packageOverrides self super else { })
+            // {
+              # Ceph still references cython_0 in nixpkgs; map it to modern cython on py3.13.
+              cython_0 = super.cython;
+            };
+        });
+    };
+in {
+  # Work around nixos-unstable eval failure:
+  # sphinx-9.1.0 not supported for interpreter python3.11
+  # (seen through libvirtd -> qemu_full -> ceph Python dependency chain).
+  ceph = prev.ceph.override {
+    python311 = python313ForCeph;
+  };
+}