I resolved this now on Ubuntu / Linux by resetting UFW rules.
stevee@Inspiron-1501:/www/vhosts/moodle$ sudo ufw reset
Resetting all rules to installed defaults. Proceed with operation (y|n)? y
Backing up 'user.rules' to '/lib/ufw/user.rules.20140317_163047'
...
stevee@Inspiron-1501:/www/vhosts/moodle$ sudo ufw enable
Firewall is active and enabled on system startup
stevee@Inspiron-1501:/www/vhosts/moodle$ sudo ufw default deny incoming
Default incoming policy changed to 'deny'
(be sure to update your rules accordingly)
stevee@Inspiron-1501:/www/vhosts/moodle$ sudo ufw default deny outgoing
Default outgoing policy changed to 'deny'
(be sure to update your rules accordingly)
stevee@Inspiron-1501:/www/vhosts/moodle$ sudo ufw allow out 53
Rule added
stevee@Inspiron-1501:/www/vhosts/moodle$ sudo ufw allow in 80/tcp
Rule added
stevee@Inspiron-1501:/www/vhosts/moodle$ sudo ufw allow out 80/tcp
Rule added
stevee@Inspiron-1501:/www/vhosts/moodle$ sudo ufw allow out 443/tcp
Rule added
stevee@Inspiron-1501:/www/vhosts/moodle$ sudo ufw allow out 22/tcp
Rule added
stevee@Inspiron-1501:/www/vhosts/moodle$ sudo ufw allow out 9418/tcp
Rule added
stevee@Inspiron-1501:/www/vhosts/moodle$ git clone -v git://git.moodle.org/moodle.git
Cloning into moodle...
^Cmote: Counting objects: 148052