diff -Nru xsystem35-1.7.3-pre5/debian/bin/freetype-config xsystem35-1.7.3-pre5/debian/bin/freetype-config
--- xsystem35-1.7.3-pre5/debian/bin/freetype-config	2018-11-05 21:19:30.000000000 +0000
+++ xsystem35-1.7.3-pre5/debian/bin/freetype-config	2023-01-30 20:24:12.000000000 +0000
@@ -12,9 +12,12 @@
 LC_ALL=C
 export LC_ALL
 
+if [ x"$PKG_CONFIG" = x ]; then
+    PKG_CONFIG="/usr/bin/pkg-config"
+fi
 
 # if `pkg-config' is available, use values from `freetype2.pc'
-/usr/bin/pkg-config --atleast-pkgconfig-version 0.24 >/dev/null 2>&1
+"$PKG_CONFIG" --atleast-pkgconfig-version 0.24 >/dev/null 2>&1
 if test $? -eq 0 ; then
   # note that option `--variable' is not affected by the
   # PKG_CONFIG_SYSROOT_DIR environment variable
@@ -23,17 +26,17 @@
     export PKG_CONFIG_SYSROOT_DIR
   fi
 
-  prefix=`/usr/bin/pkg-config --variable prefix freetype2`
-  exec_prefix=`/usr/bin/pkg-config --variable exec_prefix freetype2`
+  prefix=`$PKG_CONFIG --variable prefix freetype2`
+  exec_prefix=`$PKG_CONFIG --variable exec_prefix freetype2`
 
-  includedir=`/usr/bin/pkg-config --variable includedir freetype2`
-  libdir=`/usr/bin/pkg-config --variable libdir freetype2`
+  includedir=`$PKG_CONFIG --variable includedir freetype2`
+  libdir=`$PKG_CONFIG --variable libdir freetype2`
 
-  version=`/usr/bin/pkg-config --modversion freetype2`
+  version=`$PKG_CONFIG --modversion freetype2`
 
-  cflags=`/usr/bin/pkg-config --cflags freetype2`
-  dynamic_libs=`/usr/bin/pkg-config --libs freetype2`
-  static_libs=`/usr/bin/pkg-config --static --libs freetype2`
+  cflags=`$PKG_CONFIG --cflags freetype2`
+  dynamic_libs=`$PKG_CONFIG --libs freetype2`
+  static_libs=`$PKG_CONFIG --static --libs freetype2`
 else
   prefix="/usr"
   exec_prefix="/usr"
diff -Nru xsystem35-1.7.3-pre5/debian/changelog xsystem35-1.7.3-pre5/debian/changelog
--- xsystem35-1.7.3-pre5/debian/changelog	2022-12-26 12:38:29.000000000 +0000
+++ xsystem35-1.7.3-pre5/debian/changelog	2023-01-30 20:24:12.000000000 +0000
@@ -1,3 +1,16 @@
+xsystem35 (1.7.3-pre5-10) unstable; urgency=low
+
+  [ Ying-Chun Liu (PaulLiu) <paulliu@debian.org> ]
+  * Upload Helmut's debdiff.
+  [ Helmut Grohne <helmut@subdivi.de> ]
+  * Fix FTCBFS: (Closes: #958676)
+    + Use the host's pkg-config in debian/esd-config and
+      debian/bin/freetype-config.
+    + Export PKG_CONFIG for the earlier scripts.
+    + Also kill broken copy macros/gtk-2.0.m4.
+
+ -- Ying-Chun Liu (PaulLiu) <paulliu@debian.org>  Tue, 31 Jan 2023 04:24:12 +0800
+
 xsystem35 (1.7.3-pre5-9) unstable; urgency=low
 
   * Remove broken embedded copy of AM_PATH_GLIB_2_0 (Closes: #958676)
diff -Nru xsystem35-1.7.3-pre5/debian/clean xsystem35-1.7.3-pre5/debian/clean
--- xsystem35-1.7.3-pre5/debian/clean	2022-12-26 12:33:49.000000000 +0000
+++ xsystem35-1.7.3-pre5/debian/clean	2023-01-30 20:24:12.000000000 +0000
@@ -26,6 +26,7 @@
 macros/lib-ld.m4
 macros/isc-posix.m4
 macros/glib-2.0.m4
+macros/gtk-2.0.m4
 libltdl/config.h
 libltdl/config.status
 libltdl/libtool
diff -Nru xsystem35-1.7.3-pre5/debian/esd-config xsystem35-1.7.3-pre5/debian/esd-config
--- xsystem35-1.7.3-pre5/debian/esd-config	2019-11-27 09:29:30.000000000 +0000
+++ xsystem35-1.7.3-pre5/debian/esd-config	2023-01-30 20:22:51.000000000 +0000
@@ -1,3 +1,7 @@
 #!/bin/sh
 
-pkg-config libpulse-simple "$@"
+if [ x"$PKG_CONFIG" = x ]; then
+    PKG_CONFIG="pkg-config"
+fi
+
+"$PKG_CONFIG" libpulse-simple "$@"
diff -Nru xsystem35-1.7.3-pre5/debian/rules xsystem35-1.7.3-pre5/debian/rules
--- xsystem35-1.7.3-pre5/debian/rules	2019-11-27 14:54:59.000000000 +0000
+++ xsystem35-1.7.3-pre5/debian/rules	2023-01-30 20:24:12.000000000 +0000
@@ -1,6 +1,9 @@
 #!/usr/bin/make -f
 # -*- makefile -*-
 
+include /usr/share/dpkg/buildtools.mk
+export PKG_CONFIG
+
 # Uncomment this to turn on verbose mode.
 #export DH_VERBOSE=1