pantheon.switchboard-plug-a11y: hardcode path to onboard-settings

pkgs/desktops/pantheon/apps/switchboard-plugs/a11y/default.nix

@@ -1,4 +1,5 @@
 { stdenv
+, substituteAll
 , fetchFromGitHub
 , pantheon
 , meson
@@ -9,6 +10,7 @@
 , granite
 , gtk3
 , switchboard
+, onboard
 }:
 
 stdenv.mkDerivation rec {
@@ -22,6 +24,13 @@ stdenv.mkDerivation rec {
     sha256 = "1wh46lrsliii5bbvfc4xnzgnii2v7sqxnbn43ylmyqppfv9mk1wd";
   };
 
+  patches = [
+    (substituteAll {
+      src = ./fix-paths.patch;
+      inherit onboard;
+    })
+  ];
+
   passthru = {
     updateScript = pantheon.updateScript {
       repoName = pname;

pkgs/desktops/pantheon/apps/switchboard-plugs/a11y/fix-paths.patch

@@ -0,0 +1,13 @@
+diff --git a/src/Panes/Typing.vala b/src/Panes/Typing.vala
+index b4ae8b0..5b8fd7e 100644
+--- a/src/Panes/Typing.vala
++++ b/src/Panes/Typing.vala
+@@ -83,7 +83,7 @@ public class Accessibility.Panes.Typing : Categories.Pane {
+ 
+         onboard_settings_label.clicked.connect (() => {
+             try {
+-                var appinfo = AppInfo.create_from_commandline ("onboard-settings", null, AppInfoCreateFlags.NONE);
++                var appinfo = AppInfo.create_from_commandline ("@onboard@/bin/onboard-settings", null, AppInfoCreateFlags.NONE);
+                 appinfo.launch (null, null);
+             } catch (Error e) {
+                 warning ("%s\n", e.message);