Storage size of fdset unknown

[Richard Pyne]

I know this is a little off topic, but the Lunar bunch being 
some of the most knowledgable and helpful folks around, i 
thought I'd ask.

I am trying to compile axconv.c on a Lunar linux-2.6 box and 
keep getting an error of Storage size of 'fdset' is unknown.

The offending line in axconv.c is:
  struct fd_set fdset;

fd_set is defined in /usr/include/sys/select.h

>From the gcc preprocessor output, it looks like:

typedef struct
  {
    __fd_mask __fds_bits[1024 / (8 * sizeof (__fd_mask))];
  } fd_set;

Any insights at fixing this will be greatly appreciated. i am 
under the gun to get this whole thing up and running quickly for 
an emergency exercise on thursday.

Thanks.

--Richard