Log X errors

features/manager/x_errors.feature

@@ -0,0 +1,17 @@
+Feature: X errors logging
+
+  Scenario: logs error details
+    Given a file named layout.rb with:
+      """
+      class Layout
+        def register _; end
+
+        # Focusing a client before mapping will force an error
+        def << client
+          client.focus
+        end
+      end
+      """
+    And uhwm is running with options -v -r./layout -l Layout
+    When a window requests to be mapped
+    Then the output must match /x.*error.+x_setinputfocus.+/i