Since automake 1.12.4, the warnings are issued on running automake:
warning: 'INCLUDES' is the old name for 'AM_CPPFLAGS' (or '*_CPPFLAGS')
Avoid INCLUDES and roll these flags into AM_CPPFLAGS.
Compile tested on:
Ubuntu 10.04 (automake 1:1.11.1-1)
Ubuntu 12.04 (automake 1:1.11.3-1ubuntu2)
Arch Linux (automake 1.12.4)