ENOTSUP            24 maint/gnulib/lib/at-func.c #  define ENOTSUP EINVAL
ENOTSUP            68 maint/gnulib/lib/errno.in.h #   define ENOTSUP   129
ENOTSUP           213 maint/gnulib/lib/errno.in.h #  define ENOTSUP   2007