rns: add optional dependency lxmf (#528085)

pkgs/by-name/rn/rns/package.nix

@@ -1 +1,20 @@
-{ python3Packages }: with python3Packages; toPythonApplication rns
+{
+  python3Packages,
+}:
+
+let
+  pythonPackages = python3Packages.overrideScope (
+    self: super: {
+      lxmf = super.lxmf.override {
+        propagateRns = false;
+      };
+    }
+  );
+in
+pythonPackages.toPythonApplication (
+  pythonPackages.rns.overridePythonAttrs (old: {
+    dependencies = old.dependencies ++ [
+      pythonPackages.lxmf
+    ];
+  })
+)

pkgs/development/python-modules/lxmf/default.nix

@@ -2,6 +2,9 @@
   lib,
   buildPythonPackage,
   fetchFromGitHub,
+  # rns optionally depends on lxmf but we can't have two versions of rns in a closure
+  propagateRns ? false,
+  qrcode,
   rns,
   setuptools,
   versionCheckHook,
@@ -24,11 +27,22 @@ buildPythonPackage (finalAttrs: {
 
   pythonRelaxDeps = [ "rns" ];
 
-  dependencies = [ rns ];
+  buildInputs = lib.optionals (!propagateRns) [
+    rns
+  ];
+
+  dependencies = [
+    qrcode
+  ]
+  ++ lib.optionals propagateRns [
+    rns
+  ];
 
   pythonImportsCheck = [ "LXMF" ];
 
-  nativeCheckInputs = [ versionCheckHook ];
+  nativeCheckInputs = lib.optionals propagateRns [
+    versionCheckHook
+  ];
 
   meta = {
     description = "Lightweight Extensible Message Format for Reticulum";