AC_ARG_WITH([rpi-include-path],
[AS_HELP_STRING([--with-rpi-include-path],
[location of the Raspberry Pi headers (location of /opt/vc/include, default is auto)])],
AC_ARG_WITH([rpi-include-path],
[AS_HELP_STRING([--with-rpi-include-path],
[location of the Raspberry Pi headers (location of /opt/vc/include, default is auto)])],