In git bash for windows, the username and/or password is asked in a separate UI popup prompt like below.
On Hitting Cancel you get the below shell based prompt
Try to blank the variable core.askPass
globally (in your config-file)
$ git config --global core.askPass ""
or use the -c
switch to override it just for one command
$ git -c core.askPass="" clone
see: https://git-scm.com/docs/gitcredentials
Note: un-setting the core.askPass
by using git config --global --unset core.askPass
doesn't help. It needs to be set to an empty string like above.