Obtained from: https://github.com/keepassx/keepassx/pull/214

From 40220fd61c4094ae16d8a4d86df2b5d84c16e6e8 Mon Sep 17 00:00:00 2001
From: Anuraag Sridhar <anuraag.sridhar@gmail.com>
Date: Sun, 12 Aug 2018 14:23:33 +1000
Subject: [PATCH] Fix build issues with Qt5.11 on OS X.

Minor forward declaration issues.

--- src/gui/entry/EditEntryWidget.h.orig
+++ src/gui/entry/EditEntryWidget.h
@@ -18,6 +18,7 @@
 #ifndef KEEPASSX_EDITENTRYWIDGET_H
 #define KEEPASSX_EDITENTRYWIDGET_H
 
+#include <QButtonGroup>
 #include <QModelIndex>
 #include <QScopedPointer>
 
--- src/gui/entry/EntryView.h.orig
+++ src/gui/entry/EntryView.h
@@ -18,6 +18,7 @@
 #ifndef KEEPASSX_ENTRYVIEW_H
 #define KEEPASSX_ENTRYVIEW_H
 
+#include <QHeaderView>
 #include <QTreeView>
 
 #include "gui/entry/EntryModel.h"