What version of webkitgtk2 do you have? Can you make sure
`pkg-config` is
finding gtk+-3.0 and webkit2gtk-4.0? I think <stdlib.h> and
co. should be
included by gtk and webkit2gtk.
pkg-config --cflags gtk+-3.0
-pthread -I/usr/include/gtk-3.0 -I/usr/include/at-spi2-atk/2.0
-I/usr/include/at-spi-2.0 -I/usr/include/dbus-1.0
-I/usr/lib/dbus-1.0/include -I/usr/include/gtk-3.0
-I/usr/include/gio-unix-2.0/ -I/usr/include/cairo
-I/usr/include/pango-1.0 -I/usr/include/atk-1.0
-I/usr/include/cairo -I/usr/include/pixman-1
-I/usr/include/freetype2 -I/usr/include/libpng16
-I/usr/include/harfbuzz -I/usr/include/glib-2.0
-I/usr/lib/glib-2.0/include -I/usr/include/freetype2
-I/usr/include/harfbuzz -I/usr/include/libdrm
-I/usr/include/libpng16 -I/usr/include/gdk-pixbuf-2.0
-I/usr/include/libpng16 -I/usr/include/glib-2.0
-I/usr/lib/glib-2.0/include
pkg-config --libs webkit2gtk-4.0
-lwebkit2gtk-4.0 -lgtk-3 -lgdk-3 -lpangocairo-1.0 -lpango-1.0
-latk-1.0 -lcairo-gobject -lcairo -lgdk_pixbuf-2.0 -lsoup-2.4
-lgio-2.0 -lgobject-2.0 -ljavascriptcoregtk-4.0 -lglib-2.0
I think it is finding.