diff -pruN 6.4.2-2/debian/changelog 6.4.2-2ubuntu1/debian/changelog
--- 6.4.2-2/debian/changelog	2023-05-22 13:48:50.000000000 +0000
+++ 6.4.2-2ubuntu1/debian/changelog	2023-05-23 04:42:29.000000000 +0000
@@ -1,3 +1,9 @@
+qt6-svg (6.4.2-2ubuntu1) mantic; urgency=medium
+
+  * Mark a ppc64el symbol optional to fix FTBFS on launchpad buildds.
+
+ -- Rik Mills <rikmills@kde.org>  Tue, 23 May 2023 05:42:29 +0100
+
 qt6-svg (6.4.2-2) unstable; urgency=medium
 
   * Team upload.
diff -pruN 6.4.2-2/debian/control 6.4.2-2ubuntu1/debian/control
--- 6.4.2-2/debian/control	2023-05-22 13:25:40.000000000 +0000
+++ 6.4.2-2ubuntu1/debian/control	2023-05-23 04:42:29.000000000 +0000
@@ -1,7 +1,8 @@
 Source: qt6-svg
 Section: libs
 Priority: optional
-Maintainer: Debian Qt/KDE Maintainers <debian-qt-kde@lists.debian.org>
+Maintainer: Ubuntu Developers <ubuntu-devel-discuss@lists.ubuntu.com>
+XSBC-Original-Maintainer: Debian Qt/KDE Maintainers <debian-qt-kde@lists.debian.org>
 Uploaders: Patrick Franz <deltaone@debian.org>, Lu YaNing <dluyaning@gmail.com>
 Build-Depends: cmake (>= 3.24~),
                debhelper-compat (= 13),
diff -pruN 6.4.2-2/debian/libqt6svg6.symbols 6.4.2-2ubuntu1/debian/libqt6svg6.symbols
--- 6.4.2-2/debian/libqt6svg6.symbols	2023-05-22 13:25:40.000000000 +0000
+++ 6.4.2-2ubuntu1/debian/libqt6svg6.symbols	2023-05-23 04:42:08.000000000 +0000
@@ -287,7 +287,7 @@ libQt6Svg.so.6 libqt6svg6 #MINVER#
  _ZNK16QSvgTinyDocument13elementExistsERK7QString@Base 6.2.0
  _ZNK16QSvgTinyDocument15boundsOnElementERK7QString@Base 6.2.0
  _ZNK16QSvgTinyDocument19transformForElementERK7QString@Base 6.2.0
- _ZNK16QSvgTinyDocument4sizeEv@Base 6.2.0
+ (optional)_ZNK16QSvgTinyDocument4sizeEv@Base 6.2.0
  _ZNK16QSvgTinyDocument4typeEv@Base 6.2.0
  _ZNK16QSvgTinyDocument7svgFontERK7QString@Base 6.2.0
  _ZNK16QSvgTinyDocument8animatedEv@Base 6.2.0