xfce4-panel source package does not compile in ubuntu 20.04

After extracting the source package with apt-get source xfce4-panel,
and addeing the build dependencies with apt -y build-dep xfce4-panel,
I try to compile it with dpkg-buildpackage -b --no-sign, but get:

libtool: link: ( cd ".libs" && rm -f "libxfce4panel-2.0.la" && ln -s "../libxfce4panel-2.0.la" "libxfce4panel-2.0.la" )
CPPFLAGS="-Wdate-time -D_FORTIFY_SOURCE=2 -DNDEBUG -DHAVE_GNUC_VISIBILITY" CFLAGS="-g -O2 -fdebug-prefix-map=/home/obelix/tmp/3/xfce4-panel-4.14.3=. -fstack-protector-strong -Wformat -Werror=format-security" LDFLAGS="-Wl,-Bsymbolic-functions -Wl,-z,relro -Wl,-z,now -Wl,--as-needed -Wl,-O1 -Wl,--as-needed -Wl,-O1" CC="gcc" PKG_CONFIG="/usr/bin/pkg-config" GI_HOST_OS="" DLLTOOL="false" CC="gcc" /usr/bin/g-ir-scanner --add-include-path=. --add-include-path=/usr/share/gir-1.0 --warn-all --identifier-prefix=Xfce --identifier-prefix=xfce --identifier-prefix=LIBXFCE4PANEL --identifier-prefix=libxfce4panel --identifier-prefix=Plugin --c-include=libxfce4panel/libxfce4panel.h --namespace=libxfce4panel --nsversion=2.0 --libtool="/bin/bash ../libtool" --include=GObject-2.0 --include=GLib-2.0 --include=Gtk-3.0 --include=libxfce4util-1.0 --pkg-export=libxfce4panel-2.0 --library=libxfce4panel-2.0.la --cflags-begin -I.. -DG_LOG_DOMAIN=\"libxfce4panel\" -DLIBXFCE4PANEL_COMPILATION -DPACKAGE_LOCALE_DIR=\"/usr/share/locale\" --cflags-end libxfce4panel-enum-types.h libxfce4panel-alias.h libxfce4panel-aliasdef.c libxfce4panel-enum-types.c libxfce4panel-marshal.c libxfce4panel-marshal.h libxfce4panel.h libxfce4panel-config.h libxfce4panel-enums.h xfce-arrow-button.h xfce-panel-convenience.h xfce-panel-macros.h xfce-panel-macros-46.h xfce-panel-plugin.h xfce-panel-plugin-provider.h xfce-panel-image.h libxfce4panel-config.c xfce-arrow-button.c xfce-panel-convenience.c xfce-panel-plugin.c xfce-panel-plugin-provider.c xfce-panel-image.c libxfce4panel-2.0.la Makefile --output libxfce4panel-2.0.gir
Couldn't find include 'libxfce4util-1.0.gir' (search path: '['.', '/usr/share/gir-1.0', '/usr/share', '/usr/share/xubuntu/gir-1.0', '/usr/share/xfce4/gir-1.0', '/usr/local/share/gir-1.0', '/usr/share/gir-1.0', '/usr/share/gir-1.0', '/usr/share/gir-1.0', '/usr/share/gir-1.0']')
make[4]: *** [/usr/share/gobject-introspection-1.0/Makefile.introspection:156: libxfce4panel-2.0.gir] Error 1
make[4]: *** Waiting for unfinished jobs....
make[4]: Leaving directory '/home/obelix/tmp/3/xfce4-panel-4.14.3/libxfce4panel'
make[3]: *** [Makefile:891: all] Error 2
make[3]: Leaving directory '/home/obelix/tmp/3/xfce4-panel-4.14.3/libxfce4panel'
make[2]: *** [Makefile:612: all-recursive] Error 1
make[2]: Leaving directory '/home/obelix/tmp/3/xfce4-panel-4.14.3'
make[1]: *** [Makefile:523: all] Error 2
make[1]: Leaving directory '/home/obelix/tmp/3/xfce4-panel-4.14.3'
dh_auto_build: error: make -j4 returned exit code 2
make: *** [debian/rules:15: build] Error 2
dpkg-buildpackage: error: debian/rules build subprocess returned exit status 2

The error is Couldn't find include 'libxfce4util-1.0.gir'. I reproduce this on multiple machines.