makefile should be modify

[ytfrdfiw]

add content to Makefile
CFLAGS += -I/usr/include/glib-2.0/
CFLAGS += -I/usr/lib/x86_64-linux-gnu/glib-2.0/include/
CFLAGS += -I/usr/include/gtk-3.0/
CFLAGS += -fPIC

[ilammy]

These two lines should add necessary flags when compiling the shared library:

linux-crt/Makefile

Lines 22 to 23 in f21b7f5

	libpayload.so: payload.c
	$(CC) $(CFLAGS) -o $@ -shared $^ $(shell pkg-config --cflags --libs gtk+-3.0)

Please make sure that you have pkg-config installed.