I have installed the current version (0.25.0), and trying to do a first clone, working from cygwin, I get:

$ git tfs quick-clone http://some.name:123/ "\$/Blah/blah/Current"
Item has already been added. Key in dictionary: 'GIT_PAGER'  Key being added: 'GIT_PAGER'

I do have a GIT_PAGER environment variable, and unsetting it seems to make things work.