home: gdb: fix configuration path

Turns out the latest version of `gdb` does not yet look for its
configuration in `XDG_CONFIG_HOME`...

home/gdb/default.nix

@@ -5,13 +5,38 @@ in
 {
   options.my.home.gdb = with lib; {
     enable = my.mkDisableOption "gdb configuration";
+
+    rr = {
+      enable = my.mkDisableOption "rr configuration";
+
+      package = mkOption {
+        type = types.package;
+        default = pkgs.rr;
+        defaultText = literalExample "pkgs.rr";
+        description = ''
+          Package providing rr
+        '';
+      };
+    };
   };
 
-  config = lib.mkIf cfg.enable {
+  config = lib.mkMerge [
+    (lib.mkIf cfg.enable {
       home.packages = with pkgs; [
         gdb
       ];
 
+      # FIXME: waiting for commit 64aaad6349d2b2c45063a5383f877ce9a3a0c354
       xdg.configFile."gdb/gdbinit".source = ./gdbinit;
-  };
+
+      # FIXME: remove once `gdb` is updated from version 10.2
+      home.file.".gdbinit".source = ./gdbinit;
+    })
+
+    (lib.mkIf cfg.rr.enable {
+      home.packages = [
+        cfg.rr.package
+      ];
+    })
+  ];
 }

home/gdb/gdbinit

@@ -19,4 +19,4 @@ set print demangle on
 set auto-load python-scripts
 
 # Allow autoloading project-local .gdbinit files
-add-auto-load-safe-path ~/git/
+set auto-load safe-path ~/git/