http://74shkqooxyomdaqa5cfmqaqnxkqp25wsqilpndcik5wbhpds6uqqxeqd.onion/gitlab.freedesktop.org/vanfanel/weston/-/blob/1.4/configure.ac
xcb_xkb_save_CFLAGS=$CFLAGS
CFLAGS=$X11_COMPOSITOR_XKB_CFLAGS
AC_CHECK_MEMBER([struct xcb_xkb_state_notify_event_t.xkbType],
[], [have_xcb_xkb=no], [[#include <xcb/xkb.h>]])
CFLAGS=$xcb_xkb_save_CFLAGS
fi
if test "x$have_xcb_xkb" = xyes; then
X11_COMPOSITOR_MODULES="$X11_COMPOSITOR_MODULES xcb-xkb"
AC_DEFINE([HAVE_XCB_XKB], [1], [libxcb supports XKB protocol])
fi
PKG_CHECK_MODULES(X11_COMPOSITOR, [$X11_COMPOSITOR_MODULES])
AC_DEFINE([BUILD_X11_COMPOSITOR],...