'Unable to find remote helper'

Been beating my head against this for a while:

Here's the problem I have:

$ git submodule init
$ git submodule update
Cloning into contrib/express...
fatal: Unable to find remote helper for 'http'
Clone of 'http://github.com/visionmedia/express.git' into submodule path
'contrib/express' failed


I have git version 1.7.3.1, built from source on FreeBSD 6.4
Prior to building I have curl and expat lib installed.

My git build commands are:
./configure
gmake clean && gmake all
gmake install

I've also tried the configure as follows:
./configure --with-curl=/usr/local --with-expat=/usr/local

in case it was looking elsewhere.  The behaviour I see in this case is
identical.

Philip B.