Build failure with glade 3.36.0

With glade 3.36.0 building libhandy with glade integration fails with:

 ninja: job failed: gcc -Iglade/fe02414@@glade-handy@sha -Iglade -I../glade -I. -I.. -Isrc -I../src -I/usr/include/glib-2.0 -I/usr/lib/glib-2.0/include -I/usr/include/libmount -I/usr/include/blkid -I/usr/include/gtk-3.0 -I/usr/include/pango-1.0 -I/usr/include/harfbuzz -I/usr/include/freetype2 -I/usr/include/libpng16 -I/usr/include/fribidi -I/usr/include/uuid -I/usr/include/cairo -I/usr/include/pixman-1 -I/usr/include/gdk-pixbuf-2.0 -I/usr/include/gio-unix-2.0 -I/usr/include/libdrm -I/usr/include/atk-1.0 -I/usr/include/at-spi2-atk/2.0 -I/usr/include/dbus-1.0 -I/usr/lib/dbus-1.0/include -I/usr/include/at-spi-2.0 -I/usr/include/libgladeui-2.0 -I/usr/include/libxml2 -I/builds/Leo/aports/community/libhandy/src/libhandy-v0.0.13/output -fdiagnostics-color=always -pipe -D_FILE_OFFSET_BITS=64 -std=gnu11 -DHAVE_CONFIG_H -DHANDY_COMPILATION -Wcast-align -Wdate-time -Wdeclaration-after-statement -Werror=format-security -Werror=format=2 -Wendif-labels -Werror=incompatible-pointer-types -Werror=missing-declarations -Werror=overflow -Werror=return-type -Werror=shift-count-overflow -Werror=shift-overflow=2 -Werror=implicit-fallthrough=3 -Wformat-nonliteral -Wformat-security -Winit-self -Wmaybe-uninitialized -Wmissing-field-initializers -Wmissing-include-dirs -Wmissing-noreturn -Wnested-externs -Wno-missing-field-initializers -Wno-sign-compare -Wno-strict-aliasing -Wno-unused-parameter -Wold-style-definition -Wpointer-arith -Wredundant-decls -Wshadow -Wstrict-prototypes -Wswitch-default -Wswitch-enum -Wtype-limits -Wundef -Wunused-function -Os -fomit-frame-pointer -Os -fomit-frame-pointer -fPIC -pthread -MD -MQ 'glade/fe02414@@glade-handy@sha/glade-hdy-swipe-group.c.o' -MF 'glade/fe02414@@glade-handy@sha/glade-hdy-swipe-group.c.o.d' -o 'glade/fe02414@@glade-handy@sha/glade-hdy-swipe-group.c.o' -c ../glade/glade-hdy-swipe-group.c
../glade/glade-hdy-swipe-group.c: In function 'glade_hdy_swipe_group_read_widgets':
../glade/glade-hdy-swipe-group.c:48:46: error: 'GPC_OBJECT_DELIMITER' undeclared (first use in this function)
   48 |           g_strdup_printf ("%s%s%s", string, GPC_OBJECT_DELIMITER,
      |                                              ^~~~~~~~~~~~~~~~~~~~