AC_PATH_PROG([KEXEC], [kexec], [/usr/sbin/kexec], [$PATH:/usr/sbin:/sbin])
+AS_IF([! ln --relative --help > /dev/null 2>&1], [AC_MSG_ERROR([*** ln doesn't support --relative ***])])
+
M4_DEFINES=
# gtkdocize greps for '^GTK_DOC_CHECK', so it needs to be on its own line