fink update was failing with the following error about head missing a -n option:

cc1plus: warning: "-Wbad-function-cast" is valid for C/ObjC but not for 
 C++
 cursesfile=`echo "#include <curses.h>" | \
       gcc-3.3 -E - | grep "curses.h" | head -n 1 | \
       sed -e "s/^[^"]*"//; s/".*$//"`; \
 if [ "$cursesfile" = "" ]; then echo "can"t find curses file"; exit 1; 
 fi; \
 perl /sw/src/dpkg-1.10.21-215/dpkg-1.10.21/dselect/mkcurkeys.pl 
 keyoverride $cursesfile > curkeys.h
 Unknown option: n
 Usage: head [-options] <url>...
  -m <method>   use method for the request (default is "HEAD")
  -f            make request even if head believes method is illegal
  -b <base>     Use the specified URL as base
  -t <timeout>  Set timeout value
  -i <time>     Set the If-Modified-Since header on the request
  -c <conttype> use this content-type for POST, PUT, CHECKIN
  -a            Use text mode for content I/O
  -p <proxyurl> use this as a proxy
  -P            don"t load proxy settings from environment
  -H <header>   send this HTTP header (you can specify several)

  -u            Display method and URL before any response
  -U            Display request headers (implies -u)
  -s            Display response status code
  -S            Display response status chain
  -e            Display response headers
  -d            Do not display content
  -o <format>   Process HTML content in various ways

  -v            Show program version
  -h            Print this message

  -x            Extra debugging output
 can"t find curses file

It turns out that the issue is that when you install perl LWP it installs HEAD, GET and POST into /usr/bin. Mac OSX uses HFS+ which is case insensitive - this then overwrites the normal head utility.

I moved the HEAD/GET/POST utilities to /usr/local/bin and grabbed the head utility from a different mac box - this solved the problem.