HI Jerry,
I just had the exact same problem. I found I was using an out of date connection url for the github repository. It was git://git.moodle.org/moodle.git. I changed my git config to use git@github.com:moodle/moodle.git and it works fine. Funny because the old url worked just a few days ago but my machine has been reinstalled and it hasn't worked since. All the other urls use the newer format.
Colin