Building yhc on MAC OS X

Hi,

I am trying to build yhc on my mac. I have ghc 6.4.1 installed and gcc
4.0.1. However, when configuring I get the following message:

...
Checking for GHC binary... (cached) "/Users/cmb21/bin/ghc"
Checking for GHC version 6.4.1 or later... (cached) Found version 6.4.1.
Checking whether byte ordering is bigendian... (cached) no
Checking size of char... (cached) no
Checking size of short... (cached) no
Checking size of int... (cached) no
Checking size of long... (cached) no
Checking size of long long... (cached) no
Checking size of float... (cached) no
Checking size of double... (cached) no
Checking size of void*... (cached) no
Failed to check types sizes/endianness. You do have a working C compiler
don't you?
If so then please contact the Yhc developers for help.
dhcp2938:~/yhc cmb21$

I'm not sure what the problem is here; could someone help please?

Kind regards,

Chris Brown.